开关稳压电源-外文翻译
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史上最全的开关电源专业英语词汇展开全文史上最全的开关电源专业英语词汇母线:Busbar输电线:TransmissionLine发电厂:power plant断路器:Breaker刀闸(隔离开关):Isolator分接头:tap电动机:motor状态参数有功:active power无功:reactive power电流:current容量:capacity电压:voltage档位:tap position有功损耗:reactive loss无功损耗:active loss功率因数:power-factor功率:power功角:power-angle电压等级:voltage grade空载损耗:no-load loss铁损:iron loss铜损:copper loss空载电流:no-load current阻抗:impedance正序阻抗:positive sequenceimpedance负序阻抗:negative sequence impedance零序阻抗:zero sequence impedance电阻:resistor电抗:reactance电导:conductance电纳:susceptance无功负载:reactive load 或者QLoad有功负载: active load PLoad遥测:YC(telemetering)遥信:YX励磁电流(转子电流):magnetizing current定子:stator功角:power-angle上限:upper limit下限:lower limit并列的:apposable高压: high voltage低压:low voltage中压:middle voltage电力系统 power system发电机 generator励磁 excitation励磁器 excitor电压 voltage电流 current母线 bus变压器 transformer升压变压器 step-up transformer高压侧 high side输电系统 power transmission system输电线 transmission line固定串联电容补偿fixed series capacitor compensation稳定 stability电压稳定 voltage stability功角稳定 angle stability暂态稳定 transient stability电厂 power plant能量输送 power transfer交流 AC装机容量 installed capacity电网 power system落点 drop point开关站 switch station双回同杆并架double-circuit lines on the same tower变电站 transformer substation补偿度 degree of compensation高抗 high voltage shunt reactor无功补偿reactive power compensation故障 fault调节 regulation裕度 magin三相故障 three phase fault故障切除时间 fault clearing time极限切除时间 critical clearing time切机 generator triping高顶值 high limited value强行励磁 reinforced excitation线路补偿器LDC(line drop compensation)机端 generator terminal静态 static (state)动态 dynamic (state)单机无穷大系统 one machine - infinity bus system机端电压控制 AVR电抗 reactance电阻 resistance功角 power angle有功(功率) active power无功(功率) reactive power功率因数 power factor无功电流 reactive current下降特性 droop characteristics斜率 slope额定 rating变比 ratio参考值 reference value电压互感器 PT分接头 tap下降率 droop rate仿真分析 simulation analysis传递函数 transfer function框图 block diagram受端 receive-side裕度 margin同步 synchronization失去同步 loss of synchronization 阻尼 damping摇摆 swing保护断路器 circuit breaker电阻:resistance电抗:reactance阻抗:impedance电导:conductance电纳:susceptance导纳:admittance电感:inductance电容: capacitance电源英语词汇(三)coupling 耦合intermittent 周期的dislocation 错位propeller 螺旋桨switchgear 配电装置dispersion 差量flange 法兰盘dielectric 介电的binder 胶合剂alignment 定位elastomer 合成橡胶corollary 必然的结果rabbet 插槽vent 通风孔subtle 敏感的gearbox 变速箱plate 电镀crucial 决定性的flexible 柔性的technics 工艺ultimate 最终的resilience 弹性vendor 自动售货机partition 分类rigid 刚性的prototype 样机diagram 特性曲线interfere 干涉compatible 兼容的simulation 模拟clutch 离合器refinement 精加工fixture 夹具torque 扭矩responsive 敏感的tensile 拉伸cushion 减震器rib 肋strength 强度packing 包装metallized 金属化stress 应力mitigate 减轻trade off 折衷方案yield 屈伸line shaft 中间轴matrix 母体inherent 固有的spindle 主轴aperture 孔径conformance 适应性axle 心轴turbulence 扰动specification 规范semipermanent 半永久性的enclosure 机壳specialization 规范化bolt 螺栓oscillation 振幅calling 职业nut 螺母anneal 退火vitalize 激发screw 螺丝polymer 聚合体revelation 揭示fastner 紧固件bind 凝固dissemination 分发rivit 铆钉mount 支架booster 推进器hub 轴套distortion 变形contractual 契约的coaxial 同心的module 模块verdict 裁决crank 曲柄slide 滑块malfunction 故障inertia 惰性medium 介质allegedly 假定active 活性的dissipation 损耗controversy 辩论lubrication 润滑assembly 总装dictate 支配graphite 石墨encapsulate 封装incumbent 义不容辞的derivative 派生物adhesive 粘合剂validation 使生效contaminate 沾染turbine 涡轮procurement 收购asperity 粗糙bearing 支撑架mortality 失败率metalworking 金属加工isostatic 均衡的shed light on 阐明viscous 粘稠的osculate 接触adversely 有害的grinding 研磨imperative 强制的consistency 连续性corrosin 侵蚀lattice 晶格fitness 适应性flush 冲洗fracture 断裂warrant 保证inhibitor 防腐剂diffusivity 扩散率turning 车工dispersant 分散剂vice versa 反之亦然ways 导轨deteriorate 降低tribological 摩擦的hybrid 混合物neutralize 平衡screen 屏蔽ID=inside diameterpulley 滑轮exclusion 隔绝OD=outside diameter hydraulic 液压的insulation 绝缘reciprocate 往复运动delicate 精密的elaborate 加工dress 精整dampen 阻尼incontrovertible 无可争议的by and large 大体上pivotal 中枢的luminous 发光的plastic 塑胶utilitarian 功利主义out of round 失园organic 有机的grass root 基层premature 过早的film 薄膜state-of-the -art 技术发展水平guard 防护罩polyester 聚酯blade 托板permeate 渗入epoxy 环氧的carrier 载体spillage 溢出polypropylene 聚丙烯chuck 卡盘erosion 浸蚀photoconductive 光敏的infeed 横向进给routine 程序miniaturization 小型化lapping 抛光postprocess 后置处理asynchronism 异步milling 洗削solder-bump 焊点synchronization 同步speciality 专业grid 栅格respond 响应stroke 行程impedance 阻抗feedback 反馈attachment 备件approximately 大约aberrance 畸变tapered 楔形的purported 据说steady 稳态的casting 铸件consumable 消费品dynamic 动态的index 换档inductance 电感transient 瞬态的stop 挡块capacitance 电容coordinate 坐标contour 轮廓resistance 电容curve 曲线machine center 加工中心audion 三极管diagram 特性曲线capitalize 投资diode 二极管history 关系曲线potentiometer 电位器transistor 晶体管gradient 斜率know-how 实践知识choker 扼流圈parabola 抛物线potted 封装的filter 滤波器root 根mechatronics 机电一体化transformer 变压器eigenvalue 特征值stem from 起源于fuse 保险丝function 函数rule-based 基于规则的annular core 磁环vector 向量consolidation 巩固radiator 散热器reciprocal 倒数energize 激发regulator 稳压器virtual value 有效值synchronous 同时发生bobbin 骨架square root 平方根socket 插孔tape 胶带cube 立方polarity 极性ceramic capacitor 瓷片电容integral 积分armature 电枢electrolytic C 电解电容differential 微分installment 分期付款self-tapping screw 自攻螺丝hisgram 直方图lobe 凸起footprint 封装ratio 比率plunge 钻入resin 松香grade down 成比例降低servo 伺服机构solderability 可焊性proportion 比例dedicated 专用的shock 机械冲击inverse ratio 反比interpolation 插补endurance 耐久性direct ratio 正比compensation 校正initial value 初始值plus 加upload 加载flashing 飞弧subtract 减overload 过载canned 千篇一律的multiply 乘lightload 轻载lot 抽签divide 除stagger 交错排列parallel 并联impedance 阻抗traverse 横向in series 串联damp 阻尼longitudinal 纵向的equivalent 等效的reactance 电抗latitudinal 横向的terminal 终端admittance 导纳restrain 约束creep 蠕动susceptance 电纳square 平方Hyperlink 超级连接spring 触发memo 备忘录wastage 损耗presentation 陈述principle 原理binder 打包planer 刨床source program 源程序Client-Server Model客户机server 服务器table 表query 查询form 表单report 报表macro 宏module 模块field 字段record 记录。
附录1 外文翻译外文资料Switched-mode power supplyA switched-mode power supply (also switching-mode power supply, SMPS, or simply switcher) is an electronic power supply unit (PSU) that incorporates a switching regulator. While a linear regulator maintains the desired output voltage by dissipating excess power in a pass power transistor, the switched-mode power supply switches a power transistor between saturation (full on) and cutoff (completely off) with a variable duty cycle whose average is the desired output voltage. It switches at a much-higher frequency (tens to hundreds of kHz) than that of the AC line (mains), which means that the transformer that it feeds can be much smaller than one connected directly to the line/mains. Switching creates a rectangular waveform that typically goes to the primary of the transformer; typically several secondaries feed rectifiers, series inductors, and filter capacitors to provide various DC outputs with low ripple. The main advantage of this method is greater efficiency because the switching transistor dissipates little power in the saturated state and the off state compared to the semiconducting state (active region). Other advantages include smaller size and lighter weight (from the elimination of low frequency transformers which have a high weight) and lower heat generation due to higher efficiency. Disadvantages include greater complexity, the generation of high amplitude, high frequency energy that the low-pass filter must block to avoid electromagnetic interference (EMI), and a ripple voltage at the switching frequency and the harmonic frequencies thereof.A note about terminologyAlthough the term "power supply" has been in use since radios were first powered from the line/mains, that does not mean that it is a source of power, in the sense that a battery provides power. It is simply a device that (usually) accepts commercial AC power and provides one or more DC outputs. It would be more correctly referred to as a power converter, but long usage has established the term.ClassificationSMPS can be classified into four types according to the input and output waveforms: AC in, DC out: rectifier, off-line converter input stage DC in, DC out: voltage converter, or current converter, or DC to DC converter.AC in, AC out: frequency changer, cycloconverter, transformer DC in, AC out: inverterInput rectifier stageIf the SMPS has an AC input, then the first stage is to convert the input to DC. This is called rectification. The rectifier circuit can be configured as a voltage doubler by the addition of a switch operated either manually or automatically. This is a feature of larger supplies to permit operation from nominally 120 volt or 240 volt supplies. The rectifier produces an unregulated DC voltage which is then sent to a large filter capacitor. The current drawn from the mains supply by this rectifier circuit occurs in short pulses around the AC voltage peaks. These pulses have significant high frequency energy which reduces the power factor. Special control techniques can be employed by the following SMPS to force the average input current to follow the sinusoidal shape of the AC input voltage thus the designer should try correcting the power factor. An SMPS with a DC input does not require this stage. An SMPS designed for AC input can often be run from a DC supply (for 230V AC this would be 330V DC), as the DC passes through the rectifier stage unchanged. It's however advisable to consult the manual before trying this, though most supplies are quite capable of such operation even though nothing is mentioned in the documentation. However, this type of use may be harmful to the rectifier stage as it will only utilize half of diodes in the rectifier for the full load. This may result in overheating of thesecomponents, and cause them to fail prematurely. If an input range switch is used, the rectifier stage is usually configured to operate as a voltage doubler when operating on the low voltage (~120 V AC) range and as a straight rectifier when operating on the high voltage (~240 V AC) range. If an input range switch is not used, then a full-wave rectifier is usually used and the downstream inverter stage is simply designed to be flexible enough to accept the wide range of dc voltages that will be produced by the rectifier stage. In higher-power SMPSs, some form of automatic range switching may be used.Inverter stageThe inverter stage converts DC, whether directly from the input or from the rectifier stage described above, to AC by running it through a power oscillator, whose output transformer is very small with few windings at a frequency of tens or hundreds of kilohertz (kHz). The frequency is usually chosen to be above 20 kHz, to make it inaudible to humans. The output voltage is optically coupled to the input and thus2very tightly controlled. The switching is implemented as a multistage (to achieve high gain) MOSFET amplifier. MOSFETs are a type of transistor with a low on-resistance and a high current-handling capacity. Since only the last stage has a large duty cycle, previous stages can be implemented by bipolar transistors leading to roughly the same efficiency. The second last stage needs to be of a complementary design, where one transistor charges the last MOSFET and another one discharges the MOSFET. A design using a resistor would run idle most of the time and reduce efficiency. All earlier stages do not weight into efficiency because power decreases by a factor of 10 for every stage (going backwards) and thus the earlier stages are responsible for at most 1% of the efficiency. This section refers to the block marked Chopper in the block diagram.Voltage converter and output rectifierIf the output is required to be isolated from the input, as is usually the case in mains power supplies, the inverted AC is used to drive the primary winding of a high-frequency transformer. This converts the voltage up or down to the required output level on its secondary winding. The output transformer in the block diagramserves this purpose. If a DC output is required, the AC output from the transformer is rectified. For output voltages above ten volts or so, ordinary silicon diodes are commonly used. For lower voltages, Schottky diodes are commonly used as the rectifier elements; they have the advantages of faster recovery times than silicon diodes (allowing low-loss operation at higher frequencies) and a lower voltage drop when conducting. For even lower output voltages, MOSFETs may be used as synchronous rectifiers; compared to Schottky diodes, these have even lower conducting state voltage drops. The rectified output is then smoothed by a filter consisting of inductors and capacitors. For higher switching frequencies, components with lower capacitance and inductance are needed. Simpler, non-isolated power supplies contain an inductor instead of a transformer. This type includes boost converters, buck converters, and the so called buck-boost converters. These belong to the simplest class of single input, single output converters which utilize one inductor and one active switch. The buck converter reduces the input voltage in direct proportion to the ratio of conductive time to the total switching period, called the duty cycle. For example an ideal buck converter with a 10 V input operating at a 50% duty cycle will produce an average output voltage of 5 V. A feedback control loop is employed to regulate the output voltage by varying the dutycycle to compensate for variations in input voltage. The output voltage of a boost converter is always greater than the input voltage and the buck-boost output voltage is inverted but can be greater than, equal to, or less than the magnitude of its input voltage. There are many variations and extensions to this class of converters but these three form the basis of almost all isolated and non-isolated DC to DC converters. By adding a second inductor the uk and SEPIC converters can be implemented, or, by adding additional active switches, various bridge converters can be realised. Other types of SMPSs use a capacitor-diode voltage multiplier instead of inductors and transformers. These are mostly used for generating high voltages at low currents (Cockcroft-Walton generator). The low voltage variant is called charge pump.RegulationA feedback circuit monitors the output voltage and compares it with a referencevoltage, which is set manually or electronically to the desired output. If there is an error in the output voltage, the feedback circuit compensates by adjusting the timing with which the MOSFETs are switched on and off. This part of the power supply is called the switching regulator. The Chopper controller shown in the block diagram serves this purpose. Depending on design/safety requirements, the controller may or may not contain an isolation mechanism (such as opto-couplers) to isolate it from the DC output. Switching supplies in computers, TVs and VCRs have these opto-couplers to tightly control the output voltage. Open-loop regulators do not have a feedback circuit. Instead, they rely on feeding a constant voltage to the input of the transformer or inductor, and assume that the output will be correct. Regulated designs compensate for the parasitic capacitance of the transformer or coil. Monopolar designs also compensate for the magnetic hysteresis of the core. The feedback circuit needs power to run before it can generate power, so an additional non-switching power-supply for stand-by is added.Transformer designSMPS transformers run at high frequency. Most of the cost savings (and space savings) in off-line power supplies come from the fact that a high frequency transformer is much smaller than the 50/60 Hz transformers formerly used. There are several differences in the design of transformers for 50 Hz vs 500 kHz. Firstly a low frequency transformer usually transfers energy through its core (soft iron), while the (usually ferrite) core of a high frequency transformer limits leakage.Since the waveforms in a SMPS are generally high speed (PWM square waves), the wiring must be capable of supporting high harmonics of the base frequency due to the skin effect, which is a major source of power loss.Power factorSimple off-line switched mode power supplies incorporate a simple full wave rectifier connected to a large energy storing capacitor. Such SMPSs draw current from the AC line in short pulses when the mains instantaneous voltage exceeds the voltage across this capacitor. During the remaining portion of the AC cycle the capacitor provides energy to the power supply. As a result, the input current of such basicswitched mode power supplies has high harmonic content and relatively low power factor. This creates extra load on utility lines, increases heating of the utility transformers and standard AC electric motors, and may cause stability problems in some applications such as in emergency generator systems or aircraft generators. Harmonics can be removed through the use of filter banks but the filtering is expensive, and the power utility may require a business with a very low power factor to purchase and install the filtering onsite. In 2001 the European Union put into effect the standard IEC/EN61000-3-2 to set limits on the harmonics of the AC input current up to the 40th harmonic for equipment above 75 W. The standard defines four classes of equipment depending on its type and current waveform. The most rigorous limits (class D) are established for personal computers, computer monitors, and TV receivers. In order to comply with these requirements modern switched-mode power supplies normally include an additional power factor correction (PFC) stage. Putting a current regulated boost chopper stage after the off-line rectifier (to charge the storage capacitor) can help correct the power factor, but increases the complexity (and cost).Quasiresonant ZCS/ZVSA quasiresonant ZCS/ZVS switch (Zero Current/Zero V oltage) is a design where "each switch cycle delivers a quantized 'packet' of energy to the converter output, and switch turn-on and turn-off occurs at zero current and voltage, resulting in an essentially lossless switch."EfficiencyHigher input voltage and synchronous rectification mode makes the conversion process more efficient. Higher switch frequency allows component size to be shrunk,but suffer from radio frequency (RF) properties on the other hand. The power consumption of the controller also has to be taken into account.ApplicationsSwitched-mode PSUs in domestic products such as personal computers often have universal inputs, meaning that they can accept power from most mains supplies throughout the world, with rated frequencies from 50 Hz to 60 Hz and voltages from 100 V to 240 V (although a manual voltage range switch may be required). In practicethey will operate from a much wider frequency range and often from a DC supply as well. In 2006, at an Intel Developers Forum, Google engineers proposed the use of a single 12 V supply inside PCs, due to the high efficiency of switch mode supplies directly on the PCB. Most modern desktop and laptop computers already have a DC-DC converter on the motherboard, to step down the voltage from the PSU or the battery to the CPU core voltage, as low as 0.8 V for a low voltage CPU to 1.2-1.5 V for a desktop CPU as of 2007. Most laptop computers also have a DC-AC inverter to step up the voltage from the battery to drive the backlight, typically around 1000 Vrms. Certain applications, such as in automobile industry where ordinary cars often use 12 V DC and in some industrial settings, DC supply is chosen to avoid hum and interference and ease the integration of capacitors and batteries used to buffer the voltage. Most small aircraft use 28 V DC, but larger aircraft like Boeing-747 often use up to 90 kV A 3-phase at 200 V AC 400 Hz, though they often have a DC bus as well. Even fighter planes like F-16 use 400 Hz power. The MD-81 airplane has an 115/200 V 400 Hz AC and 28 VDC power system generated by three 40 kV A AC generators. Helicopters also use the 28 VDCsystem. Some submarines like the Soviet Alfa class submarine utilized two synchronous generators providing a variable three-phase current, 2 x 1500 kW, 400 V, 400 Hz. The space shuttle uses three fuel cells generating 30 - 36 VDC. Some is converted into 400 Hz AC power and 28 VDC power. The International Space Station uses 120 VDC power. Larger trucks uses 24 V DC. See also: Avionics, Airplane ground support In the case of TV sets, for example, one can test the excellent regulation of the power supply by using a variac. For example, in some models made by Philips, the power supply starts when the voltage reaches around 90 volts. From there, one can change the voltage with the variac, and go as low as 40 volts and as high as 260 (known such case that voltage was 360), and the image will show absolutely no alterations.TerminologyThe term switchmode was widely used until Motorola trademarked SWITCHMODE(TM), for products aimed at the switching-mode power supply market, and started to enforce their trademark[19].中文译文开关模式电源开关模式电源(也开关式电源,开关电源,或只是交换机)是一种电子电源供应器(电源),包含了开关稳压器。
NC switching power supplyAbstractThis system based on 51 SCM control unit, used for LM2576-wild numerical control a switching power supply of fuzzy digital control technology, adjust load R1, R2 proportion to change occupies empties compared to make the output stability, and can be through the buttons, digital display to realize output voltage numerical control. In addition, the system to input pressure, flow, input output flow, switch tube overheat as well as the protection circuit, ensure that the system is stable and reliable.Key words: the numerical control switch power supply,LM2576-wild microcontrollerThe first chapter tasks and requirements(a) The taskDesign and construction of a switching power supply, its structure diagram shown as shown in figure 1(b) Requirements1, basic requirements(1) Basic specifications: input voltage: + 10 V/DC (fluctuating range 8 to 12 V)Output voltage: + 2.5 V/DC ~ + 6.5 V/DC(2)The basic technical index:The output of subsection power shift, and 8 from + 2.5 V to 6.5 V +, and every 0.5 V increase. Namely (2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6)Efficiency: 70% (p < + 2.5 V/DC, 1 A testing accurate)Maximum output current: 2 A; Voltage adjustment rate: 2% or less; Current adjust rate: 2% or less(3) Can be arbitrary tuned to the requirements of the output voltage, and with a certain way of the display.(4) can be arbitrary through the keyboard control open/close the output voltage.2. Play a part(1)Have over-voltage protection, input voltage protection movement, there are 15 V over current protection, more than 3 A output current protection movement(2) Improve efficiency: 80% (p < circuit to + 2.5 V/DC, 2 A testing accurate)(3)The ripple: 1% or less (+ 2.5 V/DC, 2 A 20 MHz oscilloscope testing accurate)(4) Press from low to high or from high to low order automatically change the output voltage, each file 2 ~ 3 seconds, between time and space in the test.The second chapter scheme comparison and selectionPlan 1:the division components, such as Self-excitation switching power supply, the circuit principle diagram is as follows:The input voltage for AC220v, 50 Hz ac alternating current, after filtering, again by rectifier bridge after rectifying into a dc, through the control circuit switch tube conduction and globe make high frequency transformer of a low voltage measurement produce high-frequency voltage, small power by high-frequency transformer coupling to second test, then through rectifier filter, get dc voltage output. In order to make the output voltage stability, with the TL431 sampling error, the optical coupling amplifier, through the PWM to control switch tube conduction and deadline (i.e. occupies empties compared), makes the output voltage remain stable.From the foregoing, this scheme circuit is more complex, difficult, so don't debugging feasible.Plan2:DC-DC transform the BUCK type with A/D converter, and constantly testing power output voltage, depending on the power supply output voltage and of the difference of the set value, use of PWM module PWM waves in output, direct control of the power supply. ARM extended buttons, digital display to realize the numerical control output voltage.This scheme is simple, but all the circuit by division components, interference; And PWM module single-chip microcomputer control program is complicated, consider 52 and A/D program between factors, will cause the output of the PWM delay, distortion, so that the output voltage is not quite stable, and so on.Plan 3: the special chip power LM2576-such as wild, its typical circuit are as follows:LM2576 series of stabilizer which are monolithic integrated circuit, can provide the buck switching voltage regulators (buck) all sorts of functions, can drive 3 A load, have excellent linear and load adjustment ability, and LM2576 stabilizer interior contains frequency compensation device and A fixed frequency as its, the number of the external components can be minimized, and easy to use.This scheme, 220 V / 50 Hz ac voltage after rectifying circuit and DC/DC voltage chip LM2576 wild transformation for stable-DC voltage, and then through the adjustment of the relationship of scale and R2 R1 to adjust LM2576 chip of the input output voltage stability than empty. An external circuit components number less, and the program is simple, and the output voltage stability is good.Through various program, feasibility, complexity, system index comparative advantages and disadvantages of each scheme, comprehensive, we use the third plan.In the third chapter of the system hardware design(a)The design of the whole system1. The design thoughtSystem to monolithic integrated circuit AT89S52, LM2576-for the core part, and the wild through the monolithic integrated circuit to output voltage gather, comparison, operations, and the output voltage control, automatic regulation system structure diagram shown as shown in figure 1.220 V / 50 Hz ac voltage after rectifying circuit and DC/DC voltage chip LM2576 wild transformation for stable-5 ~ 12 V DC voltage output, the output voltage through sampling circuit by sampling, A/D conversion chip ADC0804 after converting to 52 after processing, control simulation electron switch to choose 4051 respectively the nine potentiometer R2, change R1 and R2 ratio values, which change LM2576-of the wild chip PWM pulse of empty, MOS tubes work than to switch state in, the input of 15 V DC voltage "chopped" for the and of the same frequency PWM waves pulse wave, pulse wave through the rectifier filter circuit output for 5 ~ 12 V DC voltage. Because of this the topic request have nine output stepping demand, so can tune in advance each voltage resistance, through the corresponding key choice output voltage, directly to the analog switch 4067 choose resistance, they can get to output voltage. At the same time, to detect the voltage, current value through the display LCD1062 real-time display. If working current is too big, the flow detection circuit will be sent to the testing results of single-chip microcomputer, SCM control relay through the ac branch realize over-current protection system in fault, after the operation is set by the reset button to may cause the system to resume normal work.2. The block diagram of the whole system(b) Unit circuit function and the analysis of the operation1. Minimum AT89S52 SCM systemMinimum system including crystal oscillator circuit and reset switch and power supply parts. Figure 2 for the minimum AT89S52 SCM system.2. Rectifier circuit.The wave rectifier circuit is made up of two half wave of rectifier circuit. Because in the next two, add on miens input voltage of the opposite polarity, therefore, to a dynamic balance, in every signal cycle, the C1 and C2 experience 2 times charger, discharge process, current will appear two current pulse with polarity. So in addition to the V o saw tooth wave on the wavy frequency, improve the ability of double filtering, thus reduce ripple voltage.3.Power supply circuitThe dc power by power supply, filtering, protection, such as voltage, four basic modules.(1)The power transformer USES a step-down transformer, the power grid voltage 220 V transform into need ac voltage. The ac voltageAfter rectifying, may obtain electronic equipment need dc voltage.(2) Use rectifier circuit bridge rectifier circuit single-phase, 50 Hz ac alternating current transformation for direction invariable but still has the pulse size straight Flow electricity. Its advantage is high voltage ripple voltage, small, the utilization rate of transformer high. This design by A bridge pile of bridge rectifier, RS808 do maximum current can reach 8 A, cooperate with the design of the large filter capacitance, so the power of the instantaneous large current power supply characteristics, low noise, good reaction speed, output ripple small.(3)Filter circuit using capacitance filter circuit, will the pulsation of the rectifier circuit output filter, get most of the components is smooth dc the electricity. This circuit adopts 4700 u F / 50 V large capacitance C3, C4 to make the output voltage more smooth, the power supply characteristics moment, suitable for take the perceptual load, such as motor start-up. C3, C4 every parallel connection a 0.1 u F / 63 V CBB capacitance, filter to high frequency interference, make input to integrated circuits L11, L12 of dc as far as possible the smooth and pure.(4)By LM317 output voltage circuit is power, LM337 output negative supply. LM317 and LM337 are used internal heat Load, contains over current protection, hot off and safety working area for perfect protection circuit, that power can save the fuse, and so easy loss device. Regulating circuit: to meet the needs of the differentapplication situation and the voltage is set to can be adjusted. The calculation of the output voltage Vo = 1.25 x (1 + Rf/R), adjustable resistance in use precision can be resistor and guarantee the precise output voltage can be adjusted. If this article chooses for 5 k of Rf Ω, R for 270 Ω combination, can respectively on 1.25 V ~ 24 V 1.25 V ~ 24 V achieve continuous adjustable between.(5)Protection circuit for linear power supply heat, so the power larger add enough radiator. Due to the high performance integrated circuit, which can simplify the circuit structure, highlighting the important part in the power transformation. Through the commissioning and testing, good performance. The whole circuit The power not only can be used alone, also can be in other electronic equipment used in voltage or current stabilization source use.4. LM2576-voltage circuit wildWorking principle:Assume that the switch transistors, diodes are ideal components, inductance and capacitance is ideal components, the output voltage ripple voltage output voltage and the ratio of the small to allow oversight.According to the current cycle to begin in IL inductance is starting from scratch, can be divided into current continuous working mode and inductance inductive current is discontinuous work patterns. Due to the continuous work mode inductance current converter, have very good control characteristic; Inductive current is discontinuous work mode, put the electric, inductance and capacitance easy to produce the oscillation, thus affecting the output voltage ripple; And the same occupies empties compared, output voltage in discrete model under the mode of work than the big, high efficiency. To sum up, the most ideal situation is in critical condition, stabilizer which work so we use two kinds of methods:(1)The increase of the inductance inductive energy storage, increase, and extend the discharge of time(2)Improve the work and reduce the frequency switch timeMake transistor in current continuous state.5. The whole wave output rectifier circuit parameter analysisOutput filter by free-wheeling diode rectifier circuit, inductance and capacitance composition. Consider free-wheeling diode in tube by PMOS transistor conduction, when energy consumption, and work in the state, so we used the low powerconsumption, high current, high-speed Scotty diodes IN5817, the characteristics as follows:Maximum peak reverse voltage: 40 VThe biggest reverse RMS voltage: 28 VThe biggest dc voltage: 40 V blockThe biggest positive average rectifier current: 1 AThe biggest positive pressure drop: 0.6 V (1 A)BUCK converter principle by analysis shows that in order to make work in inductive current circuit continuous mode, and the ripple voltage2221()88o o o s s V V D V t tT T LC LC=-= So as far as possible, should be made great inductance we choose for 8 mHinductanceCapacitors mainly is the "absorb" ripple with a smooth, the role of the voltagewaveform. Capacitance and inductance is equivalent to a low pass filtering filter, thecut-off frequency defined asfc =Considering the capacitance equivalent series resistance losses, we choose the capacitance for 1000 uF.562c f Hz ==≈ ()(2~4)gs th V V =-- At this time the cut-off frequency of about 562 Hz ac, visible to dozens of kHz PWM waves have very good filtering effect.6. Input over-voltage protectionWhen the input voltage in the normal range, the input sampling voltage comparator, less than the benchmark voltage output low level; When the input pressure, input voltage is greater than the benchmark sampling comparison output voltage, high level, ARM produce external interruption, warning, blockade, make PMOS transistor tube PWM signal, in order to protect the circuit damage.7. Over-current protectionUsually with hall current sensor detection of current directly PMOS transistor, and then with setting the Id threshold value, compared with comparison to control the output of the driver signal shut off; Or by indirect method, the flow test voltage when the voltage drop the Vsd PMOS transistor, because the pressure drop containsshort-circuit current information flow, when the Vsd increasing, and basically for linear relationship between the flow of testing, when the Vsd and with setting the threshold value is used in the comparison, the comparator output control power circuit of the shutoff.8. LCD display circuitChapter 5 system commissioning1. The software debuggingThe design of the software is more simple, only the keys and LCD display two modules. Through the key control output voltage and the change of the commissioning, a began to discover that step is sometimes 0.5 v, sometimes become 1 v, then add the delay, eliminate buttons dither program can.2. Hardware debuggingFirst of all, points module debugging. First, then debugging power moduleLM2576-and 4067 wild voltage analog switch module, first with high and low level directly elected 4067, using a millimeters to measure the output voltage is correct, after right in with 4067 single-chip microcomputer control, observation output voltage, with a screwdriver fine-tuning nine R2 resistance, change and a number of R2 R1 toadjust output voltage. Through these preliminary commissioning, the output voltage tend to be normal.3. The machine commissioning1) the output voltage can only to 5.62 v, highest can't carry it up again.Reason: analog switch of the 4067 working voltage and choose too small.The solution: the microcontroller output and 4067 a transistor, indirect transistor is in state, when transistor switch when closed, 4067 the voltage by large voltage choose, so that, once the single-chip microcomputer choose the 4067, the working voltage increase.2) Keys pressed, found the step voltage is sometimes 0.5 v, sometimes is 1 v. Reason: usually we keys pressed, there will be delay jitter effect.Solution: in the program and button in case time delay jitter program.3) when the SCM P1 mouth directly elected in 4067 the output, measured using a multimedia P1 mouth output level, found that total for the low level, will single-chip microcomputer and 4067 connections disconnected, using a multimedia after in the mouth output level, found the P1 normal.Reason: 52 chip is with a erase program after board of the smallest system directly into the general effect, choose 4067 output level will be down.The solution: the press the reset button 52 single chip can.Chapter 6 system tests1. The test project circuit2. Testing instrumentsThree and a half digital multimedia (MASTECH my61)Dc power supply (MOTECH LPS-305)Digital oscilloscopes (Tektronix TDS 1002)3. Test results1) in the input voltage for 15 V, respectively for 200 ohm load, 150 ohm, 100 ohm, output voltage accuracy of the test2) in the input voltage for 15 V, load resistance for nominal resistance (i.e. current for 500 mA), output ripple voltage and efficiency test3) the input voltage change circumstances, output voltage ripple and efficiency, precision testingFrom the table three can see, calibration constant input voltage, the higher the voltage, the ripple voltage, the greater the input current is smaller, the lower the efficiency.【reference 】[1]Gao JiXiang. Analog electronic circuit design [M]. Beijing electronic industry press, 2007[2] ZhouZhiGuang. Microcontroller technology and application [M]. Hunan zhongnanuniversity press, 2005[3] YanShi. Digital electronic technology base 【M 】higher education press. Beijing. 2004[4] PengJieHua. The "curriculum design of electronic technology [M]. Beijing guidance ofhigher education press, 1999[5] HuangYouQuan. LiGuiPing. Based on the design of many Chinese characters AT89S52display 【J 】. Electronic design engineering, 2008数控开关稳压电源摘要本系统基于51单片机为控制单元,采用LM2576-ADJ数控开关稳压电源中的模糊数字控制技术,调整负载R1,R2比例来改变占空比使输出稳定,并且可通过按键、数码显示实现输出电压数控。
本科毕业设计(论文) 外文参考文献译文及原文学院信息工程学院专业信息工程年级班别学号学生姓名指导教师目录译文 (1)基于单片机的开关电源 (1)1、用途 (1)2、简介 (1)3、分类 (2)4、开关电源的分类 (3)5、技术发展动向 (4)6、原理简介 (6)7、电路原理 (7)8、DC/DC变换 (8)9、AC/DC变换 (8)原文 (10)The design Based onsingle chip switching power supply (10)1、uses (10)2、Introduction (10)3、classification (11)4、the switching power supply. (13)5、technology developments (14)6、the principle of Introduction (17)7、the circuit schematic (18)8、the DC / DC conversion (19)9, AC / DC conversion (20)译文基于单片机的开关电源1、用途开关电源产品广泛应用于工业自动化控制、军工设备、科研设备、LED 照明、工控设备、通讯设备、电力设备、仪器仪表、医疗设备、半导体制冷制热、空气净化器,电子冰箱,液晶显示器,LED灯具,通讯设备,视听产品,安防,电脑机箱,数码产品和仪器类等领域。
2、简介随着电力电子技术的高速发展,电力电子设备与人们的工作、生活的关系日益密切,而电子设备都离不开可靠的电源,进入80年代计算机电源全面实现了开关电源化,率先完成计算机的电源换代,进入90年代开关电源相继进入各种电子、电器设备领域,程控交换机、通讯、电子检测设备电源、控制设备电源等都已广泛地使用了开关电源,更促进了开关电源技术的迅速发展。
开关电源是利用现代电力电子技术,控制开关晶体管开通和关断的时间比率,维持稳定输出电压的一种电源,开关电源一般由脉冲宽度调制(PWM)控制IC和开关器件(MOSFET、BJT等)构成。
Based on SCM controlled switchingpower supply design1.IntroductionSwitching power supply is the use of modern power electronics control the power switch (the MOSFET, the IGBT) turn-on and turn-off time ratio to stabilize the output voltage of a new power supply.A variety of electronic, electrical devices, computers, program-controlled switchboards, communications, electronic testing equipment, power, control equipment, power supply, etc. have been widely used switching power supply. Use of microprocessor controlled switching power supply, to enable the switching power supply with more functionality, intelligent to further improve the ease of real-time monitoring. Its functions include the operation of the switching power supply testing, and automatically display the power status; control button to be programmed; fault self-diagnosis, automatic monitoring of the electrical power section; overvoltage, overcurrent protection for power; real-time control and so on.2.SCM controlled switching power supply design optionsBy a microprocessor controlled switching power supply, power output control, three control methods, therefore, there are three alternative design:(1)Single-chip output voltage (DC/ AC chip or PWM mode), used as the reference voltage of the switching power supply .This program is the only single chip instead of the original reference voltage of the switching power supply, you can use the buttons to set the output voltage value, the microcontroller does not add the power of the feedback loop, the power circuit and nothing changes.In this way the easiest.(2)Combination of microcontroller and switching power supply PWM chip .This program uses the Microprocessor A / D converter continuously detect the output voltage based on the difference of the power supply output voltage settings, adjust the output of the D / A converter to control the PWM chip, and indirect control power. In this way has been added to the microcontroller power supply feedback loop, instead of the original zoom link, the microcontroller program to more complex PID algorithm.(3)Single-chip direct control type. Microprocessor AC/ DC, constantly testing the output voltage of the power supply, according to the difference of the power supply output voltage with the set value, the output PWM wave, the direct control of the power. In this way MCU intervention power.3.Optimal design of program analysis3.1 Comparison of three schemes:The first scenario: single-chip output voltage (DC / AC chip or PWM mode), used as a reference voltage of the switching power supply. This program, only single-chip instead of the original reference voltage of the switching power supply, there is no practical significance.The second option: the microcontroller to adjust the DC / AC output, control the PWM chip, indirectly, to control the power supply. The microcontroller in this program can only complete the simulation of some flexibility given, followed by the switching power supply PWM chip to get some work done. In this scenario, the microcontroller is not very high, the 51 series of microcontrollers have been capable; from cost considerations, the low price of 51 series of microcontrollers, and many PWM control chip; In addition, this program adequately address the direct control by the microcontroller the switching power supply common problem --- microcontroller output of the PWM pulse frequency is low, resulting in low accuracy, cannot meet the requirements of the problem. Therefore, the microcontroller and PWM chip combining is a completely viable solution.The third option: the most thorough single-chip control switching power supply, but the requirements on the microcontroller. Requirements of the single-chip operation speed is fast enough, and can output a high enough frequency PWM wave. DSP class of single-chip fast enough, but the price is also high, accounting for the proportion of the total cost of the power too much should not be used. Low-cost microcontroller, A VR series is the fastest, with PWM output, the A VR microcontroller's operating frequency is not high enough, can only be reluctant to use.3.2The conclusion after the comparative analysisAbove comparative analysis, I think: The second method for microcontroller andswitching power supply PWM control chip combining is the optimal design of microcontroller-based control, switching power supply.4.Based on the 89C51 microprocessor controlled switching power supplyAccording to the conclusions of the optimal design, the following cite an instance based on the optimal solution in this instance the application characteristics of typical PWM chip TL494, designing a forward converter based on microcontroller 89c51 auxiliary control switching power supply.4.1Working principle4.1.1The realization of the power supply soft start:Forward converter switching power supply input voltage is switched on, will have a strong charge current, the gentle rise of the output voltage by the soft starter. TL494 has a soft start function, at 4 feet, 14 feet indirectly capacitor can ton slowly widening, in order to achieve the soft starter.4.1.2 Adjustable output voltage regulator controlThe switching power supply with the transistor on / off (ON / OFF) to achieve the energy exchange, and its output controls, determined by the transistor on-time popular method is using PWM control, specific control transistor is turned on accountair ratio. Namely: the control of the frequency of the pulse signal has been set (cycle has been set), adjust the duty cycle is Effective level to adjust the pulse width. For example: To improve the output voltage, simply width modulated control pulse level width can be. Similarly, the regulator principle is based on this. 4-pin of the TL494 is the dead time correction terminals, and feet to set a voltage value, can get a fixed pulse width signal output. The principle is: the TL494 internal oscillator's triangle wave voltage between 0. 2V ~ 3.3V triangle wave voltage higher than the pin 4 voltage is the control signal ton. Therefore, set by adjusting the voltage of pin 4 can adjust the PWM output ton time, allowing the output voltage is adjustable. The TL494 data sheet, the control voltage is typically 4 feet dead zone: 2. 8V, corresponding Tton = 0; 0V, corresponding to the largest ton, in this voltage range corresponding to thevoltage value corresponding to a fixed pulse width output, high frequency conversion also get the corresponding voltage output, the resulting output with adjustable goal is achieved, this function is specific by the microcontroller.Adjustable output voltage, then need to be addressed is the regulator, the whole requirements of the regulation accuracy is slightly higher, to regulated by the microcontroller, microcontroller running a simple instruction takes one cycle, when the 12M crystalvibration when a cycle is 1us, is clearly inconsistent with the requirements of the closed-loop regulator, in this time can be used TL494 error amplifier built-in closed-loop regulator, the realization of the principle is the use of the voltage error amplifier voltage negative feedback circuit. Microcontroller to a given at every level need the voltage regulator reference point, in order to output a voltage, a voltage stability.4.2Hardware and software implementation4.2.1Hardware implementationThis circuit is the main control circuit tracking regulator circuit and protection circuit. The block diagram is shown below:4.2.1.1Adjustable output voltage control circuit: The realization of the circuit through the latch (74LS377) and D / A converter (DAC0800), by the microcontroller when the microcontroller to the 74LS377 into the data to the data is latched by 74LS377 beenthe DAC0800 converted output DC voltage to the TL4944 feet, given the different benchmarks regulator level, you can achieve different voltage output.4.2.1.2 Regulator reference circuit should outputThe requirements of the voltage adjustable, then must ask when the output of a voltage regulator, according to the principle of closed-loop negative feedback circuit shows (left), maintain a balanced voltage Vref is the voltage regulator reference level, Vref, and U 'onlya difference of more than a dozen millivolts, when the output voltage Uout increased, the voltage U 'value must be increased, the error amplifier output voltage will drop, making TL494 internal PWM wave output pulse width narrowing. Series of high-frequency transform filter the output voltage the Uout will reduce, so as to achieve the purpose of regulation. Make the appropriate adjustment (increase or decrease) in order to achieve the purpose of the output voltage regulation when the output voltage is artificially adjusted (increase or decrease) shall be Vref.4.2.1.3 Realization of the protection function(1)Overvoltage, undervoltage protection(2)Overvoltage, undervoltage protection circuitAs the diagram shown on the left: the overvoltage detection circuit is to use TL431. Within the TL431 with a 5V reference voltage when the input voltage B increases by the voltage sampling circuit consisting of two resistors obtained by the partial pressure is greater than 2. 5V, TL431 conduction and low output of the cathode K level, an interrupt signal to the microcontroller to cut off the output of the TL494, and display circuit to display the current state of the overvoltage protection.As the diagram shown on the right: the detection circuit use TL431 to when the input voltage B decreases, the sampling circuit consisting of two resistors voltage divider voltage is less than 2. 5V, TL431 deadline, the cathode Khigh output, an inverter, the inverter outputs a low cut off the TL494 output by the microcontroller detected, and displayed through the display circuit undervoltage protection status.Overcurrent protection circuit: As shown below: over-current protection circuit is achieved by CA3140 and a PNP transistor, when the current sampling signal performance for the over-current op amp CA3140 output of 6 feet above a high level, so that the transistor turn-off74LS32 9-pin output is high, turn off the PWM wave output of the TL494. Also to the microcontroller interrupt signal, so that the display circuit over-current protection status.4.2.2Software implementationThe software architecture of the circuit including initialization, pre-set and fault detection procedures, and core software controlled microcontroller AT89C51. Program block diagram as shown below:。
中文4060字外文文献Switched-mode power supplyA switched-mode power supply (also switching-mode power supply, SMPS, or simply switcher) is an electronic power supply unit (PSU) that incorporates a switching regulator. While a linear regulator maintains the desired output voltage by dissipating excess power in a pass power transistor, the switched-mode power supply switches a power transistor between saturation (full on) and cutoff (completely off) with a variable duty cycle whose average is the desired output voltage. It switches at a much-higher frequency (tens to hundreds of kHz) than that of the AC line (mains), which means that the transformer that it feeds can be much smaller than one connected directly to the line/mains. Switching creates a rectangular waveform that typically goes to the primary of the transformer; typically several secondaries feed rectifiers, series inductors, and filter capacitors to provide various DC outputs with low ripple.The main advantage of this method is greater efficiency because the switching transistor dissipates little power in the saturated state and the off state compared to the semiconducting state (active region). Other advantages include smaller size and lighter weight (from the elimination of low frequency transformers which have a high weight) and lower heat generation due to higher efficiency. Disadvantages include greater complexity, the generation of high amplitude, high frequency energy that the low-pass filter must block to avoid electromagnetic interference (EMI), and a ripple voltage at the switching frequency and the harmonic frequencies thereof.A note about terminologyAlthough the term "power supply" has been in use since radios were first powered from the line/mains, that does not mean that it is a source of power, in the sense that a battery provides power. It is simply a device that (usually) accepts commercial AC power and provides one or more DC outputs. It would be more correctly referred to as a power converter, but long usage has established the term. ClassificationSMPS can be classified into four types according to the input and output waveforms: AC in, DC out: rectifier, off-line converter input stageDC in, DC out: voltage converter, or current converter, or DC to DC converterAC in, AC out: frequency changer, cycloconverter, transformerDC in, AC out: inverterInput rectifier stageIf the SMPS has an AC input, then the first stage is to convert the input to DC. This is called rectification. The rectifier circuit can be configured as a voltage doubler by the addition of a switch operated either manually or automatically. This is a feature of larger supplies to permit operation from nominally 120 volt or 240 volt supplies. The rectifier produces an unregulated DC voltage which is then sent to a large filter capacitor. The current drawn from the mains supply by this rectifier circuit occurs in short pulses around the AC voltage peaks. These pulses have significant high frequency energy which reduces the power factor. Special control techniques can be employed by the following SMPS to force the average input current to follow the sinusoidal shape of the AC input voltage thus the designer should try correcting the power factor. An SMPS with a DC input does not require this stage. An SMPS designed for AC input can often be run from a DC supply (for 230V AC this would be 330V DC), as the DC passes through the rectifier stage unchanged. It's however advisable to consult the manual before trying this, though most supplies are quite capable of such operation even though nothing is mentioned in the documentation. However, this type of use may be harmful to the rectifier stage as it will only utilize half of diodes in the rectifier for the full load. This may result in overheating of these components, and cause them to fail prematurely.If an input range switch is used, the rectifier stage is usually configured to operate as a voltage doubler when operating on the low voltage (~120 V AC) range and as a straight rectifier when operating on the high voltage (~240 V AC) range. If an input range switch is not used, then a full-wave rectifier is usually used and the downstream inverter stage is simply designed to be flexible enough to accept the wide range of dc voltages that will be produced by the rectifier stage. In higher-power SMPSs, some form of automatic range switching may be used.Inverter stageThe inverter stage converts DC, whether directly from the input or from the rectifier stage described above, to AC by running it through a power oscillator, whoseoutput transformer is very small with few windings at a frequency of tens or hundreds of kilohertz (kHz). The frequency is usually chosen to be above 20 kHz, to make it inaudible to humans. The output voltage is optically coupled to the input and thus very tightly controlled. The switching is implemented as a multistage (to achieve high gain) MOSFET amplifier. MOSFETs are a type of transistor with a low on-resistance and a high current-handling capacity. Since only the last stage has a large duty cycle, previous stages can be implemented by bipolar transistors leading to roughly the same efficiency. The second last stage needs to be of a complementary design, where one transistor charges the last MOSFET and another one discharges the MOSFET. A design using a resistor would run idle most of the time and reduce efficiency. All earlier stages do not weight into efficiency because power decreases by a factor of 10 for every stage (going backwards) and thus the earlier stages are responsible for at most 1% of the efficiency. This section refers to the block marked Chopper in the block diagram.V oltage converter and output rectifierIf the output is required to be isolated from the input, as is usually the case in mains power supplies, the inverted AC is used to drive the primary winding of a high-frequency transformer. This converts the voltage up or down to the required output level on its secondary winding. The output transformer in the block diagram serves this purpose.If a DC output is required, the AC output from the transformer is rectified. For output voltages above ten volts or so, ordinary silicon diodes are commonly used. For lower voltages, Schottky diodes are commonly used as the rectifier elements; they have the advantages of faster recovery times than silicon diodes (allowing low-loss operation at higher frequencies) and a lower voltage drop when conducting. For even lower output voltages, MOSFETs may be used as synchronous rectifiers; compared to Schottky diodes, these have even lower conducting state voltage drops.The rectified output is then smoothed by a filter consisting of inductors and capacitors. For higher switching frequencies, components with lower capacitance and inductance are needed.Simpler, non-isolated power supplies contain an inductor instead of a transformer. This type includes boost converters, buck converters, and the so called buck-boost converters. These belong to the simplest class of single input, single output converters which utilize one inductor and one active switch. The buck converter reduces the input voltage in direct proportion to the ratio of conductive time to the total switchingperiod, called the duty cycle. For example an ideal buck converter with a 10 V input operating at a 50% duty cycle will produce an average output voltage of 5 V. A feedback control loop is employed to regulate the output voltage by varying the duty cycle to compensate for variations in input voltage. The output voltage of a boost converter is always greater than the input voltage and the buck-boost output voltage is inverted but can be greater than, equal to, or less than the magnitude of its input voltage. There are many variations and extensions to this class of converters but these three form the basis of almost all isolated and non-isolated DC to DC converters. By adding a second inductor the Ćuk and SEPIC converters can be implemented, or, by adding additional active switches, various bridge converters can be realised.Other types of SMPSs use a capacitor-diode voltage multiplier instead of inductors and transformers. These are mostly used for generating high voltages at low currents (Cockcroft-Walton generator). The low voltage variant is called charge pump. RegulationA feedback circuit monitors the output voltage and compares it with a reference voltage, which is set manually or electronically to the desired output. If there is an error in the output voltage, the feedback circuit compensates by adjusting the timing with which the MOSFETs are switched on and off. This part of the power supply is called the switching regulator. The Chopper controller shown in the block diagram serves this purpose. Depending on design/safety requirements, the controller may or may not contain an isolation mechanism (such as opto-couplers) to isolate it from the DC output. Switching supplies in computers, TVs and VCRs have these opto-couplers to tightly control the output voltage.Open-loop regulators do not have a feedback circuit. Instead, they rely on feeding a constant voltage to the input of the transformer or inductor, and assume that the output will be correct. Regulated designs compensate for the parasitic capacitance of the transformer or coil. Monopolar designs also compensate for the magnetic hysteresis of the core.The feedback circuit needs power to run before it can generate power, so an additional non-switching power-supply for stand-by is added.Transformer designSMPS transformers run at high frequency. Most of the cost savings (and space savings) in off-line power supplies come from the fact that a high frequency transformer is much smaller than the 50/60 Hz transformers formerly used.There are several differences in the design of transformers for 50 Hz vs 500 kHz. Firstly a low frequency transformer usually transfers energy through its core (soft iron), while the (usually ferrite) core of a high frequency transformer limits leakage. Since the waveforms in a SMPS are generally high speed (PWM square waves), the wiring must be capable of supporting high harmonics of the base frequency due to the skin effect, which is a major source of power loss.Power factorSimple off-line switched mode power supplies incorporate a simple full wave rectifier connected to a large energy storing capacitor. Such SMPSs draw current from the AC line in short pulses when the mains instantaneous voltage exceeds the voltage across this capacitor. During the remaining portion of the AC cycle the capacitor provides energy to the power supply.As a result, the input current of such basic switched mode power supplies has high harmonic content and relatively low power factor. This creates extra load on utility lines, increases heating of the utility transformers and standard AC electric motors, and may cause stability problems in some applications such as in emergency generator systems or aircraft generators. Harmonics can be removed through the use of filter banks but the filtering is expensive, and the power utility may require a business with a very low power factor to purchase and install the filtering onsite.In 2001 the European Union put into effect the standard IEC/EN61000-3-2 to set limits on the harmonics of the AC input current up to the 40th harmonic for equipment above 75 W. The standard defines four classes of equipment depending on its type and current waveform. The most rigorous limits (class D) are established for personal computers, computer monitors, and TV receivers. In order to comply with these requirements modern switched-mode power supplies normally include an additional power factor correction (PFC) stage.Putting a current regulated boost chopper stage after the off-line rectifier (to charge the storage capacitor) can help correct the power factor, but increases the complexity (and cost).Quasiresonant ZCS/ZVSA quasiresonant ZCS/ZVS switch (Zero Current/Zero Voltage) is a design where "each switch cycle delivers a quantized 'packet' of energy to the converter output, and switch turn-on and turn-off occurs at zero current and voltage, resulting in an essentially lossless switch."EfficiencyHigher input voltage and synchronous rectification mode makes the conversion process more efficient. Higher switch frequency allows component size to be shrunk, but suffer from radio frequency (RF) properties on the other hand. The power consumption of the controller also has to be taken into account.ApplicationsSwitched-mode PSUs in domestic products such as personal computers often have universal inputs, meaning that they can accept power from most mains supplies throughout the world, with rated frequencies from 50 Hz to 60 Hz and voltages from 100 V to 240 V (although a manual voltage range switch may be required). In practice they will operate from a much wider frequency range and often from a DC supply as well. In 2006, at an Intel Developers Forum, Google engineers proposed the use of a single 12 V supply inside PCs, due to the high efficiency of switch mode supplies directly on the PCB.Most modern desktop and laptop computers already have a DC-DC converter on the motherboard, to step down the voltage from the PSU or the battery to the CPU core voltage, as low as 0.8 V for a low voltage CPU to 1.2-1.5 V for a desktop CPU as of 2007. Most laptop computers also have a DC-AC inverter to step up the voltage from the battery to drive the backlight, typically around 1000 Vrms.Certain applications, such as in automobile industry where ordinary cars often use 12 V DC and in some industrial settings, DC supply is chosen to avoid hum and interference and ease the integration of capacitors and batteries used to buffer the voltage. Most small aircraft use 28 V DC, but larger aircraft like Boeing-747 often use up to 90 kV A 3-phase at 200 V AC 400 Hz, though they often have a DC bus as well. Even fighter planes like F-16 use 400 Hz power. The MD-81 airplane has an 115/200 V 400 Hz AC and 28 V DC power system generated by three 40 kV A AC generators. Helicopters also use the 28 V DC system. Some submarines like the Soviet Alfa class submarine utilized two synchronous generators providing a variable three-phase current, 2 x 1500 kW, 400 V, 400 Hz. The space shuttle uses three fuel cells generating 30 - 36 V DC. Some is converted into 400 Hz AC power and 28 V DC power. The International Space Station uses 120 V DC power. Larger trucks uses 24 V DC.See also: Avionics, Airplane ground supportIn the case of TV sets, for example, one can test the excellent regulation of thepower supply by using a variac. For example, in some models made by Philips, the power supply starts when the voltage reaches around 90 volts. From there, one can change the voltage with the variac, and go as low as 40 volts and as high as 260 (known such case that voltage was 360), and the image will show absolutely no alterations.TerminologyThe term switchmode was widely used until Motorola trademarked SWITCHMODE(TM), for products aimed at the switching-mode power supply market, and started to enforce their trademark.外文翻译开关模式电源开关模式电源(也开关式电源,开关电源,或只是交换机)是一种电子电源供应器(电源),包含了开关稳压器。
Intelligent switch power supply英文:With the rapid development of electronic technology, application field of electronic system is more and more extensive, electronic equipment, there are more and more people work with electronic equipment, life is increasingly close relationship. Any electronic equipment are inseparable from reliable power supply for power requirements, they more and more is also high. Electronic equipment miniaturized and low cost in the power of light and thin, small and efficient for development direction. The traditional transistors series adjustment manostat is continuous control linear manostat. This traditional manostat technology more mature, and there has been a large number of integrated linear manostat module, has the stable performance is good, output ripple voltage small, reliable operation, etc. But usually need are bulky and heavy industrial frequency transformer and bulk and weight are big filter.In the 1950s, NASA to miniaturization, light weight as the goal, for a rocket carrying the switch power development. In almost half a century of development process, switch power because of its small volume, light weight, high efficiency, wide range, voltage advantages in electric, control, computer, and many other areas of electronic equipment has been widely used. In the 1980s, a computer is made up of all of switch power supply, the first complete computer power generation. Throughout the 1990s, switching power supply in electronics, electrical equipment, home appliances areas to be widely, switch power technology into the rapid development. In addition, large scale integrated circuit technology, and the rapid development of switch power supply with a qualitative leap, raised high frequency power products of, miniaturization, modular tide.Power switch tube, PWM controller and high-frequency transformer is an indispensable part of the switch power supply. The traditional switch power supply is normally made by using high frequency power switch tube division and the pins, such as using PWM integrated controller UC3842 + MOSFET is domestic small powerswitch power supply, the design method of a more popularity.Since the 1970s, emerged in many function complete integrated control circuit, switch power supply circuit increasingly simplified, working frequency enhances unceasingly, improving efficiency, and for power miniaturization provides the broad prospect. Three end off-line pulse width modulation monolithic integrated circuit TOP (Three switch Line) will Terminal Off with power switch MOSFET PWM controller one package together, has become the mainstream of switch power IC development. Adopt TOP switch IC design switch power, can make the circuit simplified, volume further narrowing, cost also is decreased obviouslyMonolithic switching power supply has the monolithic integrated, the minimalist peripheral circuit, best performance index, no work frequency transformer can constitute a significant advantage switching power supply, etc. American PI (with) company in Power in the mid 1990s first launched the new high frequency switching Power supply chip, known as the "top switch Power", with low cost, simple circuit, higher efficiency. The first generation of products launched in 1994 represented TOP100/200 series, the second generation product is the TOP Switch - debuted in 1997 Ⅱ. The above products once appeared showed strong vitality and he greatly simplifies thedesign of 150W following switching power supply and the development of new products for the new job, also, high efficiency and low cost switch power supply promotion and popularization created good condition, which can be widely used in instrumentation, notebook computers, mobile phones, TV, VCD and DVD, perturbation VCR, mobile phone battery chargers, power amplifier and other fields, and form various miniaturization, density, on price can compete with the linear manostat AC/DC power transformation module.Switching power supply to integrated direction of future development will be the main trend, power density will more and more big, to process requirements will increasingly high. In semiconductor devices and magnetic materials, no new breakthrough technology progress before major might find it hard to achieve, technology innovation will focus on how to improve the efficiency and focus onreducing weight. Therefore, craft level will be in the position of power supply manufacturing higher in. In addition, the application of digital control IC is the future direction of the development of a switch power. This trust in DSP for speed and anti-interference technology unceasing enhancement. As for advanced control method, now the individual feels haven't seen practicability of the method appears particularly strong,perhaps with the popularity of digital control, and there are some new control theory into switching power supply.(1)The technology: with high frequency switching frequencies increase, switch converter volume also decrease, power density has also been boosted, dynamic response improved. Small power DC - DC converter switch frequency will rise to MHz. But as the switch frequency unceasing enhancement, switch components and passive components loss increases, high-frequency parasitic parameters and high-frequency EMI and so on the new issues will also be caused.(2)Soft switching technologies: in order to improve the efficiency of non-linearity of various soft switch, commutation technical application and hygiene, representative of soft switch technology is passive and active soft switch technology, mainly including zero voltage switch/zero current switch (ZVS/ZCS) resonance, quasi resonant, zero voltage/zero current pulse width modulation technology (ZVS/ZCS - PWM) and zero voltage transition/zero current transition pulse width modulation (PWM) ZVT/ZCT - technical, etc. By means of soft switch technology can effectively reduce switch loss and switch stress, help converter transformation efficiency (3)Power factor correction technology (IC simplifies PFC). At present mainly divided into IC simplifies PFC technology passive and active IC simplifies PFC technology using IC simplifies PFC technology two kinds big, IC simplifies PFC technology can improve AC - DC change device input power factor, reduce the harmonic pollution of power grid.(4)Modular technology. Modular technology can meet the needs of the distributed power system, enhance the system reliability.(5)Low output voltage technology. With the continuous development of semiconductor manufacturing technology, microprocessor and portable electronic devices work more and more low, this requires future DC - DC converter can provide low output voltage to adapt microprocessor and power supply requirement of portable electronic devicesPeople in switching power supply technical fields are edge developing related power electronics device, the side of frequency conversion technology, development of switch between mutual promotion push switch power supply with more than two year growth toward light, digital small, thin, low noise and high reliability, anti-interference direction. Switching powersupply can be divided into the AC/DC and DC/DC two kinds big, also have AC/AC DC/AC as inverter DC/DC converter is now realize modular, and design technology and production process at home and abroad, are mature and standardization, and has approved by users, but the AC/DC modular, because of its own characteristics in the process of making modular, meet more complex technology and craft manufacture problems. The following two types of switch power supply respectively on the structure and properties of this.Switching power supply is the development direction of high frequency, high reliability, low consumption, low noise, anti-jamming and modular. Because light switch power, small, thin key techniques are changed, so high overseas each big switch power supply manufacturer are devoted to the development of new high intelligent synchronous rectifier, especially the improvement of secondary devices of the device, and power loss of Zn ferrite (Mn) material? By increasing scientific and technological innovation, to enhance in high frequency and larger magnetic flux density (Bs) can get high magnetic under the miniaturization of, and capacitor is a key technology. SMT technology application makes switching power supply has made considerable progress, both sides in the circuitboard to ensure that decorate components of switch power supply light, small, thin. The high frequency switching power supply of the traditional PWM must innovate switch technology, to realize the ZCS ZVS, soft switch technology hasbecome the mainstream of switch power supply technical, and greatly improve the efficiency of switch power. For high reliability index, America's switch power producers, reduce by lowering operating current measures such as junction temperature of the device, in order to reduce stress the reliability of products made greatly increased.Modularity is of the general development of switch power supply trend can be modular power component distributed power system, can be designed to N + 1 redundant system, and realize the capacity expansion parallel. According to switch power running large noise this one defect, if separate the pursuit of high frequency noise will increase its with the partial resonance, and transform circuit technology, high frequency can be realized in theory and can reduce the noise, but part of the practical application of resonant conversion technology still have a technical problem, so in this area still need to carry out a lot of work, in order to make the technology to practional utilization.Power electronic technology unceasing innovation, switch power supply industry has broad prospects for development. To speed up the development of switch power industry in China, we must walk speed of technological innovation road, combination with Chinese characteristics in the joint development path, for I the high-speed development of national economy to make the contribution. The basic principle and component functionAccording to the control principle of switch power to classification, we have the following 3 kinds of work mode:1) pulse width adjustment type, abbreviation Modulation Pulse Width pulse width Modulation (PWM) type, abbreviation for. Its main characteristic is fixed switching frequency, pulse width to adjust by changing voltage 390v, realize the purpose. Its core is the pulse width modulator. Switch cycle for designing filter circuit fixed provided convenience. However, its shortcomings is influenced by the power switch conduction time limit minimum of output voltage cannot be wide range regulation; In addition, the output will take dummy loads commonly (also called pre load), in order to prevent the drag elevated when output voltage. At present, most ofthe integrated switch power adopt PWM way.2) pulse frequency Modulation mode pulse frequency Modulation (, referred to Pulse Frequency Modulation, abbreviation for PFM) type. Its characteristic is will pulse width fixed by changing switch frequency to adjust voltage 390v, realize the purpose. Its core is the pulse frequency modulator. Circuit design to use fixed pulse-width generator to replace the pulse width omdulatros and use sawtooth wave generator voltage?Frequency converter (for example VCO changes frequency VCO). It on voltage stability principle is: when the output voltage Uo rises, the output signal controller pulse width unchanged and cycle longer, make Uo 390v decreases, and reduction. PFM type of switch power supply output voltage range is very wide, output terminal don't meet dummy loads. PWM way and way of PFM respectively modulating waveform is shown in figure 1 (a), (b) shows, tp says pulse width (namely power switch tube conduction time tON), T represent cycle. It can be easy to see the difference between the two. But they have something in common: (1) all use time ratio control (TRC) on voltage stability principle, whether change tp, finally adjustment or T is pulse 390v. Although adopted in different ways, but control goals, is all rivers run into the sea. (2) when load by light weight, or input voltage respectively, from high changed by increasing the pulse width, higher frequency method to make the output voltage remained stable.3) mix modulation mode, it is to point to the pulse width and switching frequency is not fixed, each other can change, it belongs to the way the PWM and PFM blend mode. It contains a pulsewidthomdulatros and pulse frequency modulator. Because and T all can adjust alone, so occupies emptiescompared to adjust the most wide range, suitable for making the output voltage for laboratories that use a wide range of can adjust switching power supply. Above 3 work collectively referred to as "Time Ratio Control" (as a Control, from TRC) way. As noted, pulse width omdulatros either as a independent IC use (for example UC3842 type pulse width omdulatros), can also be integrated in DC/DC converter (for example LM2576 type switching voltage regulators integrated circuit), still can integration in AC/DC converter (for exampleTOP250 type monolithic integrated circuit switching power supply. Among them, the switching voltage regulators belong to DC/DC power converter, switching power supply general for AC/DC power converter.The typical structure of switch power as figure1shows, its working principle is: the first utility into power rectifier and filtering into high voltage dc and then through the switch circuit and high-frequency switch to high frequency low pressure pulse transformer, and then after rectification and filter circuits, finally output low voltage dc power. Meanwhile in the output parts have a circuit feedback to control circuit, through the control PWM occupies emptiescompared to achieve output voltage stability.Figure 1 typical structure of switch power supplySwitching power supply by these four components:1) the main circuit: exchange network input, from the main circuit to dc output. Mainly includes input filter, rectifier and filtering, inverter, and output rectifier and filtering.(1) input filter: its effect is the power grid existing clutter filtering, also hinder the machine produces clutter feedback to public power grid.(2) rectifier and filter: the power grid ac power directly for a smooth dc rectifier, for the next level transformation.(3) inverter: will the dc after rectifying a high-frequency ac, this is the core of high frequency switching power supply, the higher the frequency, the volume, weight and the ratio of power output and smaller.(4) Out put rectifier and filter: according to load needs, providing stable and reliable dc power supply. 2) control circuit: on the one hand, from the output bysampling with set standards to compare, and then to control inverter, changing its frequency or pulse width, achieve output stability, on the other hand, according to data provided by the test circuit, the protection circuit differential, provide control circuit to the machine to various protection measures. Including the output feedback circuit and sampling circuit, pulse width modulator. 3) the detection and protection circuit: detection circuit had current detection, over-voltage detection, owe voltage detection, overheat detection, etc.; Protection circuit can be divided over current protection, over-voltage protection, owe voltage protection, the ground-clamp protection, overheating protection, automatic restart, soft start, slow startup, etc. Various types. 4) Other circuit: if the sawtooth wave generator, offset circuit, optical coupler, etc.智能开关电源中文:随着电子技术的高速发展,电子系统的应用领域越来越广泛,电子设备的种类也越来越多,电子设备与人们的工作、生活的关系日益密切。
开关稳压电源开关稳压电源(以下简称开关电源)问世后,在很多领域逐步取代了线性稳压电源和晶闸管相控电源。
早期出现的是串联型开关电源,其主电路拓扑与线性电源相仿,但功率晶体管工作于开关状态。
随着脉宽调制(PWM)技术的发展,PWM开关电源问世,它的特点是用20kHz的载波进行脉冲宽度调制,电源的效率可达65%~70%,而线性电源的效率只有30%~40%。
因此,用工作频率为20 kHz的PWM开关电源替代线性电源,可大幅度节约能源,从而引起了人们的广泛关注,在电源技术发展史上被誉为20kHz革命。
随着超大规模集成(ultra-large-scale-integrated-ULSI)芯片尺寸的不断减小,电源的尺寸与微处理器相比要大得多;而航天、潜艇、军用开关电源以及用电池的便携式电子设备(如手提计算机、移动电话等)更需要小型化、轻量化的电源。
因此,对开关电源提出了小型轻量要求,包括磁性元件和电容的体积重量也要小。
此外,还要求开关电源效率要更高,性能更好,可靠性更高等。
这一切高新要求便促进了开关电源的不断发展和进步。
1 开关电源的三个重要发展阶段40多年来,开关电源经历了三个重要发展阶段。
第一个阶段是功率半导体器件从双极型器件(BPT、SCR、GT0)发展为MOS型器件(功率MOS-FET、IGBT、IGCT等),使电力电子系统有可能实现高频化,并大幅度降低导通损耗,电路也更为简单。
第二个阶段自20世纪80年代开始,高频化和软开关技术的研究开发,使功率变换器性能更好、重量更轻、尺寸更小。
高频化和软开关技术是过去20年国际电力电子界研究的热点之一。
第三个阶段从20世纪90年代中期开始,集成电力电子系统和集成电力电子模块(IPEM)技术开始发展,它是当今国际电力电子界亟待解决的新问题之一。
2 开关电源技术的亮点2.1 功率半导体器件性能1998年,Infineon公司推出冷MOS管,它采用“超级结”(Super-Junction)结构,故又称超结功率MOSFET。
电力电子技术术语Absorber Circuit 吸收电路AC/ACFrequency Converter 交交变频电路AC power control 交流电力控制AC Power Controller 交流调功电路AC Power Electronic Switch 交流电力电子开关AC Voltage Controller 交流调压电路Asynchronous Modulation 异步调制Baker Clamping Circuit 贝克箝位电路Bi-directional Triode Thyristor 双向晶闸管Bipolar Junction Transistor-- BJT 双极结型晶体管Boost—Buck Chopper 升降压斩波电路Boost Chopper 升压斩波电路Boost Converter 升压变换器Bridge Reversible Chopper 桥式可逆斩波电路Buck Chopper 降压斩波电路Buck Converter 降压变换器Commutation 换流Conduction Angle 导通角Constant Voltage Constant Frequency--CVCF恒压恒频Continuous Conduction—-CCM (电流)连续模式Control Circuit控制电路CUK Circuit CUK 斩波电路Current Reversible Chopper 电流可逆斩波电路Current Source Type Inverter-—CSTI 电流(源)型逆变电路Cycloconvertor 周波变流器DC—AC—DC Converter 直交直电路DC Chopping 直流斩波DC Chopping Circuit直流斩波电路DC-DC Converter 直流-直流变换器Device Commutation 器件换流Direct Current Control 直接电流控制Discontinuous Conduction mode (电流)断续模式Displacement Factor 位移因数Distortion Power 畸变功率Double End Converter 双端电路Driving Circuit 驱动电路Electrical Isolation 电气隔离Fast Acting Fuse 快速熔断器Fast Recovery Diode 快恢复二极管Fast Recovery Epitaxial Diodes 快恢复外延二极管Fast Switching Thyristor 快速晶闸管Field Controlled Thyristor 场控晶闸管Flyback Converter 反激电流Forced Commutation 强迫换流Forward Converter 正激电路Frequency Converter 变频器Full Bridge Converter 全桥电路Full Bridge Rectifier 全桥整流电路Full Wave Rectifier 全波整流电路Fundamental Factor 基波因数Gate Turn—Off Thyristor-—GTO可关断晶闸管General Purpose Diode 普通二极管Giant Transistor-—GTR 电力晶体管Half Bridge Converter 半桥电路Hard Switching 硬开关High Voltage IC 高压集成电路Hysteresis Comparison 带环比较方式Indirect Current Control 间接电流控制Indirect DC-DC Converter 直接电流变换电路Insulated-Gate Bipolar Transistor--IGBT 绝缘栅双极晶体管Intelligent Power Module-—IPM 智能功率模块Integrated Gate—Commutated Thyristor—-IGCT集成门极换流晶闸管Inversion 逆变Latching Effect 擎住效应Leakage Inductance 漏感Light Triggered Thyristo-——LTT 光控晶闸管Line Commutation 电网换流Load Commutation 负载换流Loop Current 环流元件设备三绕组变压器:three—column transformer ThrClnTrans 双绕组变压器:double-column transformer DblClmnTrans 电容器:Capacitor并联电容器:shunt capacitor电抗器:Reactor母线:Busbar输电线:TransmissionLine发电厂:power plant断路器:Breaker刀闸(隔离开关):Isolator分接头:tap电动机:motor状态参数有功:active power无功:reactive power电流:current容量:capacity电压:voltage档位:tap position有功损耗:reactive loss无功损耗:active loss功率因数:power—factor功率:power功角:power-angle电压等级:voltage grade空载损耗:no-load loss铁损:iron loss铜损:copper loss空载电流:no-load current阻抗:impedance正序阻抗:positive sequence impedance 负序阻抗:negative sequence impedance 零序阻抗:zero sequence impedance电阻:resistor电抗:reactance电导:conductance电纳:susceptance无功负载:reactive load 或者QLoad有功负载: active load PLoad遥测:YC(telemetering)遥信:YX励磁电流(转子电流):magnetizing current 定子:stator功角:power—angle上限:upper limit下限:lower limit并列的:apposable高压: high voltage低压:low voltage中压:middle voltage电力系统power system发电机generator励磁excitation励磁器excitor电压voltage电流current母线bus变压器transformer升压变压器step—up transformer高压侧high side输电系统power transmission system输电线transmission line固定串联电容补偿fixed series capacitor compensation 稳定stability电压稳定voltage stability功角稳定angle stability暂态稳定transient stability电厂power plant能量输送power transfer交流AC装机容量installed capacity电网power system落点drop point开关站switch station双回同杆并架double-circuit lines on the same tower 变电站transformer substation补偿度degree of compensation高抗high voltage shunt reactor无功补偿reactive power compensation故障fault调节regulation裕度magin三相故障three phase fault故障切除时间fault clearing time极限切除时间critical clearing time切机generator triping高顶值high limited value强行励磁reinforced excitation线路补偿器LDC(line drop compensation)机端generator terminal静态static (state)动态dynamic (state)单机无穷大系统one machine - infinity bus system 机端电压控制AVR电抗reactance电阻resistance功角power angle有功(功率)active power无功(功率) reactive power功率因数power factor无功电流reactive current下降特性droop characteristics斜率slope额定rating变比ratio参考值reference value电压互感器PT分接头tap下降率droop rate仿真分析simulation analysis传递函数transfer function框图block diagram受端receive—side裕度margin同步synchronization失去同步loss of synchronization 阻尼damping摇摆swing保护断路器circuit breaker电阻:resistance电抗:reactance阻抗:impedance电导:conductance电纳:susceptance导纳:admittance电感:inductance电容:capacitance一般术语电力电子变流器的型式(表1—2)电力电子开关和交流电力电子控制器电力电子设备的基本元件电力电子设备的电路和电路单元电力电子设备的运行电力电子设备的性能电力电子变流器的特性曲线稳定电源。
Pulse Width Modulator (PWM) General-Purpose TimersPWMPulse width modulation (PWM) is a powerful technique for digitally encoding analog signal levels.High-resolution counters are used to generate a square wave, and the duty cycle of the squarewave is modulated to encode an analog signal. Typical applications include switching power suppliesand motor control.The Stellaris® PWM module consists of three PWM generator blocks and a control block. The controlblock determines the polarity of the PWM signals, and which signals are passed through to the pins.Each PWM generator block produces two PWM signals that can either be independent signals(other than being based on the same timer and therefore having the same frequency) or a singlepair of complementary signals with dead-band delays inserted. The output of the PWM generationblocks are managed by the output control block before being passed to the device pins.The Stellaris® PWM module provides a great deal of flexibility. It can generate simple PWM signals,such as those required by a simple charge pump. It can also generate paired PWM signals withdead-band delays, such as those required by a half-H bridge driver. Three generator blocks canalso generate the full six channels of gate controls required by a 3-phase inverter bridge.PWM TimerThe timer in each PWM generator runs in one of two modes: Count-Down mode or Count-Up/Downmode. In Count-Down mode, the timer counts from the load value to zero, goes back to the loadvalue, and continues counting down. In Count-Up/Down mode, the timer counts from zero up to theload value, back down to zero, back up to the load value, and so on. Generally, Count-Down modeis used for generating left- or right-aligned PWM signals, while the Count-Up/Down mode is usedfor generating center-aligned PWM signals.The timers output three signals that are used in the PWM generation process: the direction signal(this is always Low in Count-Down mode, but alternates between Low and High in Count-Up/Downmode), a single-clock-cycle-width High pulse when the counter is zero, and a single-clock-cycle-widthHigh pulse when the counter is equal to the load value. Note that in Count-Down mode, the zeropulse is immediately followed by the load pulse.PWM ComparatorsThere are two comparators in each PWM generator that monitor the value of the counter; wheneither match the counter, they output a single-clock-cycle-width High pulse. When in Count-Up/Downmode, these comparators match both when counting up and when counting down; they are thereforequalified by the counter direction signal. These qualified pulses are used in the PWM generationprocess. If either comparator match value is greater than the counter load value, then that comparatornever outputs a High pulse.Figure 15-3 on page 493 shows the behavior of the counter and the relationship of these pulseswhen the counter is in Count-Down mode. Figure 15-4 on page 493 shows the behavior of the counterand the relationship of these pulses when the counter is in Count-Up/Down mode.PWM Signal GeneratorThe PWM generator takes these pulses (qualified by the direction signal), and generates two PWMsignals. In Count-Down mode, there are four events that can affect the PWM signal: zero, load,match A down, and match B down. In Count-Up/Down mode, there are six events that can affectthe PWM signal: zero, load, match A down, match A up, match B down, and match B up. The matchA or matchB events are ignored when they coincide with the zero or load events. If the match Aand match B events coincide, the first signal, PWMA, is generated based only on the match A event,and the second signal, PWMB, is generated based only on the match B event.Dead-Band GeneratorThe two PWM signals produced by the PWM generator are passed to the dead-band generator. Ifdisabled, the PWM signals simply pass through unmodified. If enabled, the second PWM signal islost and two PWM signals are generated based on the first PWM signal. The first output PWM signalis the input signal with the rising edge delayed by a programmable amount. The second outputPWM signal is the inversion of the input signal with a programmable delay added between the fallingedge of the input signal and the rising edge of this new signal.Interrupt/ADC-Trigger SelectorThe PWM generator also takes the same four (or six) counter events and uses them to generatean interrupt or an ADC trigger. Any of these events or a set of these events can be selected as asource for an interrupt; when any of the selected events occur, an interrupt is generated. Additionally,the same event, a different event, the same set of events, or a different set of events can be selectedas a source for an ADC trigger; when any of these selected events occur, an ADC trigger pulse isgenerated. The selection of events allows the interrupt or ADC trigger to occur at a specific positionwithin the PWM signal. Note that interrupts and ADC triggers are based on the raw events; delaysin the PWM signal edges caused by the dead-band generator are not taken into account.Synchronization MethodsThere is a global reset capability that can synchronously reset any or all of the counters in the PWMgenerators. If multiple PWM generators are configured with the same counter load value, this canbe used to guarantee that they also have the same count value (this does imply that the PWMgenerators must be configured before they are synchronized). With this, more than two PWM signalscan be produced with a known relationship between the edges of those signals since the countersalways have the same values.The counter load values and comparator match values of the PWM generator can be updated intwo ways. The first is immediate update mode, where a new value is used as soon as the counterreaches zero. By waiting for the counter to reach zero, a guaranteed behavior is defined, and overlyshort or overly long output PWM pulses are prevented.The other update method is synchronous, where the new value is not used until a global synchronizedupdate signal is asserted, at which point the new value is used as soon as the counter reacheszero. This second mode allows multiple items in multiple PWM generators to be updatedsimultaneously without odd effects during the update; everything runs from the old values until apoint at which they all run from the new values. The Update mode of the load and comparator matchvalues can be individually configured in each PWM generator block. It typically makes sense to usethe synchronous update mechanism across PWM generator blocks when the timers in those blocksare synchronized, though this is not required in order for this mechanism to function properly.Fault ConditionsThere are two external conditions that affect the PWM block; the signal input on the Fault pin andthe stalling of the controller by a debugger. There are two mechanisms available to handle suchconditions: the output signals can be forced into an inactive state and/or the PWM timers can bestopped.Each output signal has a fault bit. If set, a fault input signal causes the corresponding output signalto go into the inactive state. If the inactive state is a safe condition for the signal to be in for anextended period of time, thiskeeps the output signal from driving the outside world in a dangerousmanner during the fault condition. A fault condition can also generate a controller interrupt.Each PWM generator can also be configured to stop counting during a stall condition. The user canselect for the counters to run until they reach zero then stop, or to continue counting and reloading.A stall condition does not generate a controller interrupt.Output Control BlockWith each PWM generator block producing two raw PWM signals, the output control block takescare of the final conditioning of the PWM signals before they go to the pins. Via a single register,the set of PWM signals that are actually enabled to the pins can be modified; this can be used, forexample, to perform commutation of a brushless DC motor with a single register write (and withoutmodifying the individual PWM generators, which are modified by the feedback control loop). Similarly,fault control can disable any of the PWM signals as well. A final inversion can be applied to any ofthe PWM signals, making them active Low instead of the default active High.General-Purpose TimersProgrammable timers can be used to count or time external events that drive the Timer input pins.The Stellaris? General-Purpose Timer Module (GPTM) contains three GPTM blocks (Timer0, Timer1,and Timer 2). Each GPTM block provides two 16-bit timers/counters (referred to as TimerA andTimerB) that can be configured to operate independently as timers or event counters, or configuredto operate as one 32-bit timer or one 32-bit Real-Time Clock (RTC).In addition, timers can be used to trigger analog-to-digital conversions (ADC). The ADC triggersignals from all of the general-purpose timers are ORed together before reaching the ADC module,so only one timer should be used to trigger ADC events.The GPT Module is one timing resource available on the Stellaris? microcontrollers. Other timerresources include the System Timer (SysTick) and the PWM timer in thePWM module.The General-Purpose Timers provide the following features:■Three General-Purpose Timer Modules (GPTM), each of which provides two 16-bittimers/counters. Each GPTM can be configured to operate independently:–As a single 32-bit timer–As one 32-bit Real-Time Clock (RTC) to event capture–For Pulse Width Modulation (PWM)–To trigger analog-to-digital conversions■32-bit Timer modes–Programmable one-shot timer–Programmable periodic timer–Real-Time Clock when using an external 32.768-KHz clock as the input–User-enabled stalling when the controller asserts CPU Halt flag during debug–ADC event trigger■16-bit Timer modes–General-purpose timer function with an 8-bit prescaler (for one-shot and periodic modes only)–Programmable one-shot timer–Programmable periodic timer–User-enabled stalling when the controller asserts CPU Halt flag during debug–ADC event trigger■16-bit Input Capture modes–Input edge count capture270 September 04, 2010Texas Instruments-Production DataGeneral-Purpose Timers–Input edge time capture■16-bit PWM mode–Simple PWM mode with software-programmable output inversion of the PWM signaFunctional DescriptionThe main components of each GPTM block are two free-running 16-bit up/down counters (referredto as TimerA and TimerB), two 16-bit match registers, two prescaler match registers, and two 16-bitload/initialization registers and their associated control functions. The exact functionality of eachGPTM is controlled by software and configured through the register interface.Software configures the GPTM using the GPTM Configuration (GPTMCFG) register,the GPTM TimerA Mode (GPTMTAMR) register and the GPTM TimerB Mode(GPTMTBMR) register. When in one of the 32-bit modes, the timer can only act asa 32-bit timer. However, when configured in 16-bit mode, the GPTM can have its two 16-bit timersconfigured in any combination of the 16-bit modes.8.2.1 GPTM Reset ConditionsAfter reset has been applied to the GPTM module, the module is in an inactive state, and all controlregisters are cleared and in their default states. Counters TimerA and TimerB are initialized to0xFFFF, along with their corresponding load registers: the GPTM TimerA Interval Load(GPTMTAILR) register (see page 296) and the GPTM TimerB Interval Load (GPTMTBILR) register. The prescale counters are initialized to 0x00: the GPTM TimerA Prescale(GPTMTAPR) register (see page 300) and the GPTM TimerB Prescale (GPTMTBPR) register.32-Bit Timer Operating ModesThis section describes the three GPTM 32-bit timer modes (One-Shot, Periodic, and RTC) and theirconfiguration.The GPTM is placed into 32-bit mode by writing a 0 (One-Shot/Periodic 32-bit timer mode) or a 1(RTC mode) to the GPTM Configuration (GPTMCFG) register. In both configurations, certain GPTMregisters are concatenated to form pseudo 32-bit registers. These registers include:■GPTM TimerA Interval Load (GPTMTAILR) register [15:0],■GPTM TimerB Interval Load (GPTMTBILR) register [15:0],■GPTM TimerA (GPTMTAR) register [15:0],■GPTM TimerB (GPTMTBR) register [15:0],In the 32-bit modes, the GPTM translates a 32-bit write access to GPTMTAILR into a write accessto both GPTMTAILR and GPTMTBILR. The resulting word ordering for such a write operation is: GPTMTBILR[15:0]:GPTMTAILR[15:0]Likewise, a read access to GPTMTAR returns the value:GPTMTBR[15:0]:GPTMTAR[15:0]8.2.2.1 32-Bit One-Shot/Periodic Timer ModeIn 32-bit one-shot and periodic timer modes, the concatenated versions of the TimerA and TimerBregisters are configured as a 32-bit down-counter. The selection of one-shot or periodic mode isdetermined by the value written to the TAMR field of the GPTM TimerA Mode (GPTMTAMR) register, and there is no need to write to the GPTM TimerB Mode (GPTMTBMR) register.When software writes the TAEN bit in the GPTM Control (GPTMCTL) register, theimer begins counting down from its preloaded value. Once the 0x0000.0000 state is reached, thetimer reloads its start value from the concatenated GPTMTAILR on the next cycle. If configured tobe a one-shot timer, the timer stops counting and clears the TAEN bit in the GPTMCTL register. Ifconfigured as a periodic timer, it continues counting.In addition to reloading the count value, the GPTM generates interrupts and triggers when it reachesthe 0x000.0000 state. The GPTM sets the TATORIS bit in the GPTM Raw Interrupt Status(GPTMRIS) register andholds it until it is cleared by writing the GPTM InterruptClear (GPTMICR) register. If the time-out interrupt is enabled in the GPTM InterruptMask (GPTMIMR) register (see page 290), the GPTM also sets the TATOMIS bit in the GPTM MaskedInterrupt Status (GPTMMIS) register (see page 293). The ADC trigger is enabled by setting theTAOTE bit in GPTMCTL.If software reloads the GPTMTAILR register while the counter is running, the counter loads the newvalue on the next clock cycle and continues counting from the new value.If the TASTALL bit in the GPTMCTL register is set, the timer freezes counting while the processoris halted by the debugger. The timer resumes counting when the processor resumes execution.32-Bit Real-Time Clock Timer ModeIn Real-Time Clock (RTC) mode, the concatenated versions of the TimerA and TimerB registersare configured as a 32-bit up-counter. When RTC mode is selected for the first time, the counter isloaded with a value of 0x0000.0001. All subsequent load values must be written to the GPTM TimerAMatch (GPTMTAMATCHR) register by the controller.The input clock on an even CCP input is required to be 32.768 KHz in RTC mode. The clock signalis then divided down to a 1 Hz rate and is passed along to the input of the 32-bit counter.When software writes the TAEN bit inthe GPTMCTL register, the counter starts counting up from itspreloaded value of 0x0000.0001. When the current count value matches the preloaded value in theGPTMTAMA TCHR register, it rolls over to a value of 0x0000.0000 and continues counting untileither a hardware reset, or it is disabled by software (clearing the TAEN bit). When a match occurs,the GPTM asserts the RTCRIS bit in GPTMRIS. If the RTC interrupt is enabled in GPTMIMR, theGPTM also sets the RTCMIS bit in GPTMMIS and generates a controller interrupt. The status flagsare cleared by writing the RTCCINT bit in GPTMICR.If the TASTALL and/or TBSTALL bits in the GPTMCTL register are set, the timer does not freeze ifthe RTCEN bit is set in GPTMCTL.16-Bit Timer Operating ModesThe GPTM is placed into global 16-bit mode by writing a value of 0x4 to the GPTM Configuration(GPTMCFG) register. This section describes each of the GPTM 16-bit modes ofoperation. TimerA and TimerB have identical modes, so a single description is given using an n toreference both.16-Bit One-Shot/Periodic Timer ModeIn 16-bit one-shot and periodic timer modes, the timer is configured as a 16-bit down-counter withan optional 8-bit prescaler that effectively extends the counting range of the timer to 24 bits. Theselection of one-shot or periodic mode is determined by the value written to the TnMR field of theGPTMTnMR register. The optional prescaler is loaded into the GPTM Timern Prescale (GPTMTnPR)register.When software writes the TnEN bit in the GPTMCTL register, the timer begins counting down fromits preloaded value. Once the 0x0000 state is reached, the timer reloads its start value froGPTMTnILR and GPTMTnPR on the next cycle. If configured to be a one-shot timer, the timer stopscounting and clears the TnEN bit in the GPTMCTL register. If configured as a periodic timer, itcontinues counting.In addition to reloading the count value, the timer generates interrupts and triggers when it reachesthe 0x0000 state. The GPTM sets the TnTORIS bit in the GPTMRIS register, and holds it until it iscleared by writing the GPTMICR register. If the time-out interrupt is enabled in GPTMIMR, the GPTMalso sets the TnTOMIS bit in GPTMISR and generates a controller interrupt. The ADC trigger isenabled by setting the TnOTE bit in the GPTMCTL register.If software reloads the GPTMTAILR register while the counter is running, the counter loads the newvalue on the next clock cycle and continues counting from the new value.If the TnSTALL bit in the GPTMCTL register is set, the timer freezes counting while the processoris halted by the debugger. The timer resumes counting when the processor resumes execution.16-Bit Input Edge Count ModeIn Edge Count mode, the timer is configured as a down-counter capable of capturing three typesof events: rising edge, falling edge, or both. To place the timer in Edge Count mode, the TnCMR bitof the GPTMTnMR register must be set to 0. The type of edge that in theGPTMTnILR register and the GPTMTnMA TCHR register equals the number of edge events thatmust be counted.When software writes the TnEN bit in the GPTM Control (GPTMCTL) register, the timer is enabledfor event capture. Each input event on the CCP pin decrements the counter by 1 until the event countmatches GPTMTnMA TCHR. When the counts match, the GPTM asserts the CnMRIS bit in theGPTMRIS register (and the CnMMIS bit, if the interrupt is not masked).The counter is then reloaded using the value in GPTMTnILR, and stopped since the GPTMautomatically clears the TnEN bit in the GPTMCTL register. Once the event count has been reached,all further events are ignored until TnEN is re-enabled by software.16-Bit Input Edge Time ModeIn EdgeTime mode, the timer is configured as a free-running down-counter initialized to the valueloaded in the GPTMTnILR register (or 0xFFFF at reset). This mode allows for event capture ofeither rising or falling edges, but not both. The timer is placed into Edge Time mode by setting theTnCMR bit in the GPTMTnMR register, and the type of event that the timer captures is determinedby the TnEVENT fields of the GPTMCTL register.When software writes the TnEN bit in the GPTMCTL register, the timer is enabled for event capture.When the selected input event is detected, the current Tn counter value is captured in the GPTMTnRregister and is available to be read by the controller. The GPTM then asserts the CnERIS bit (andthe CnEMIS bit, if the interrupt is not masked).After an event has been captured, the timer does not stop counting. It continues to count until theTnEN bit is cleared. When the timer reaches the 0x0000 state, it is reloaded with the value from theGPTMTnILR register.16-Bit PWM ModeThe GPTM supports a simple PWM generation mode. In PWM mode, the timer is configured as adown-counter with a start value (and thus period) defined by GPTMTnILR. In this mode, the PWMfrequency and period are synchronous events and therefore guaranteed to be glitch free. PWMmode is enabled with the GPTMTnMR register by setting the TnAMS bit to 0x1, the TnCMR bit to0x0, and the TnMR field to 0x2.When software writes the TnEN bit in the GPTMCTL register, the counter begins counting downuntil it reaches the 0x0000 state. On the next counter cycle, the counter reloads its start value fromGPTMTnILR and continues counting until disabled by software clearing the TnEN bit in the GPTMCTLregister. No interrupts or status bits are asserted in PWM mode.The output PWM signal asserts when the counter is at the value of the GPTMTnILR register (itsstart state), and is deasserted when the counter value equals the value in the GPTM Timern MatchRegister (GPTMTnMATCHR). Software has the capability of inverting the output PWM signal bysetting the TnPWML bit in the GPTMCTL register.。
电工常用词汇中英文翻译]电路的基本概念及定律电源source电压源voltage source电流源current source理想电压源ideal voltage source理想电流源ideal current source伏安特性volt-ampere characteristic电动势electromotive force电压voltage电流current电位potential电位差potential difference欧姆Ohm伏特Volt安培Ampere瓦特Watt焦耳Joule电路circuit电路元件circuit element电阻resistance电阻器resistor电感inductance电感器inductor电容capacitance电容器capacitor电路模型circuit model参考方向reference direction参考电位reference potential欧姆定律Ohm’s law基尔霍夫定律Kirchhoff’s law基尔霍夫电压定律Kirchhoff’s voltage law(KVL)基尔霍夫电流定律Kirchhoff’s current law(KCL)结点node支路branch回路loop网孔mesh支路电流法branch current analysis网孔电流法mesh current analysis结点电位法node voltage analysis电源变换source transformations叠加原理superposition theorem网络network无源二端网络passive two-terminal network 有源二端网络active two-terminal network 戴维宁定理Thevenin’s theorem诺顿定理Norton’s theorem开路(断路)open circuit短路short circuit开路电压open-circuit voltage短路电流short-circuit current交流电路直流电路direct current circuit (dc)交流电路alternating current circuit (ac)正弦交流电路sinusoidal a-c circuit平均值average有效值effective均方根值root-mean-squire (rms)瞬时值instantaneous电抗reactance感抗inductive reactance容抗capacitive reactance法拉Farad亨利Henry阻抗impedance复数阻抗complex impedance相位phase初相位initial phase相位差phase difference相位领先phase lead相位落后phase lag倒相,反相phase inversion频率frequency角频率angular frequency赫兹Hertz相量phasor相量图phasor diagram有功功率active power无功功率reactive power视在功率apparent power功率因数power factor功率因数补偿power-factor compensation串联谐振series resonance并联谐振parallel resonance谐振频率resonance frequency频率特性frequency characteristic幅频特性amplitude-frequency response characteristic相频特性phase-frequency response characteristic截止频率cutoff frequency品质因数quality factor通频带pass-band带宽bandwidth (BW)滤波器filter一阶滤波器first-order filter二阶滤波器second-order filter低通滤波器low-pass filter高通滤波器high-pass filter带通滤波器band-pass filter带阻滤波器band-stop filter转移函数transfer波特图Bode diagram傅立叶级数Fourier series三相电路三相电路three-phase circuit三相电源three-phase source对称三相电源symmetrical three-phase source对称三相负载symmetrical three-phase load相电压phase voltage相电流phase current线电压line voltage线电流line current三相三线制three-phase three-wire system三相四线制three-phase four-wire system三相功率three-phase power星形连接star connection(Y-connection)三角形连接triangular connection(D- connection ,delta connection) 中线neutral line电路的暂态过程分析暂态transient state稳态steady state暂态过程,暂态响应transient response换路定理low of switch一阶电路first-order circuit三要素法three-factor method时间常数time constant积分电路integrating circuit微分电路differentiating circuit磁路与变压器磁场magnetic field磁通flux磁路magnetic circuit磁感应强度flux density磁通势magnetomotive force磁阻reluctance电动机直流电动机dc motor交流电动机ac motor异步电动机asynchronous motor同步电动机synchronous motor三相异步电动机three-phase asynchronous motor 单相异步电动机single-phase asynchronous motor 旋转磁场rotating magnetic field定子stator转子rotor转差率slip起动电流starting current起动转矩starting torque额定电压rated voltage额定电流rated current额定功率rated power机械特性mechanical characteristic继电器-接触器控制按钮button熔断器fuse开关switch行程开关travel switch继电器relay接触器contactor常开(动合)触点normally open contact常闭(动断)触点normally closed contact时间继电器time relay热继电器thermal overload relay中间继电器intermediate relay可编程控制器(PLC)可编程控制器programmable logic controller语句表statement list梯形图ladder diagram半导体器件本征半导体intrinsic semiconductor掺杂半导体doped semiconductorP型半导体P-type semiconductorN型半导体N--type semiconductor自由电子free electron空穴hole载流子carriersPN结PN junction扩散diffusion漂移drift二极管diode硅二极管silicon diode锗二极管germanium diode阳极anode阴极cathode发光二极管light-emitting diode (LED)光电二极管photodiode稳压二极管Zener diode晶体管(三极管)transistorPNP型晶体管PNP transistorNPN型晶体管NPN transistor发射极emitter集电极collector基极base电流放大系数current amplification coefficient场效应管field-effect transistor (FET)P沟道p-channelN沟道n-channel结型场效应管junction FET(JFET)金属氧化物半导体l-oxide semiconductor (MOS)耗尽型MOS场效应管depletion mode MOSFET(D-MOSFET)增强型MOS场效应管enhancement mode MOSFET(E-MOSFET)源极source栅极grid漏极drain跨导transconductance夹断电压pinch-off voltage热敏电阻thermistor开路open短路shorted基本放大器放大器amplifier正向偏置forward bias反向偏置backward bias静态工作点quiescent point (Q-point)等效电路equivalent circuit电压放大倍数voltage gain总的电压放大倍数overall voltage gain饱和saturation截止cut-off放大区amplifier region饱和区saturation region截止区cut-off region失真distortion饱和失真saturation distortion截止失真cut-off distortion零点漂移zero drift正反馈positive feedback负反馈negative feedback串联负反馈series negative feedback并联负反馈parallel negative feedback共射极放大器common-emitter amplifier射极跟随器emitter-follower共源极放大器common-source amplifier共漏极放大器common-drain amplifier多级放大器multistage amplifier阻容耦合放大器resistance-capacitance coupled amplifier 直接耦合放大器direct- coupled amplifier输入电阻input resistance输出电阻output resistance负载电阻load resistance动态电阻dynamic resistance负载电流load current旁路电容bypass capacitor耦合电容coupled capacitor直流通路direct current path交流通路alternating current path直流分量direct current component交流分量alternating current component变阻器(电位器)rheostat电阻(器)resistor电阻(值)resistance电容(器)capacitor电容(量)capacitance电感(器,线圈)inductor电感(量),感应系数inductance正弦电压sinusoidal voltage集成运算放大器及应用差动放大器differential amplifier运算放大器operational amplifier(op-amp)失调电压offset voltage失调电流offset current共模信号common-mode signal差模信号different-mode signal共模抑制比common-mode rejection ratio (CMRR) 积分电路integrator(circuit)微分电路differentiator(circuit)有源滤波器active filter低通滤波器low-pass filter高通滤波器high-pass filter带通滤波器band-pass filter带阻滤波器band-stop filter波特沃斯滤波器Butterworth filter切比雪夫滤波器Chebyshev filter贝塞尔滤波器Bessel filter截止频率cut-off frequency上限截止频率upper cut-off frequency下限截止频率lower cut-off frequency中心频率center frequency带宽Bandwidth开环增益open-loop gain闭环增益closed-loop gain共模增益common-mode gain输入阻抗input impedance电压跟随器voltage-follower电压源voltage source电流源current source单位增益带宽unity-gain bandwidth频率响应frequency response频响特性(曲线)response characteristic波特图the Bode plot稳定性stability补偿compensation比较器comparator迟滞比较器hysteresis comparator阶跃输入电压step input voltage仪表放大器instrumentation amplifier隔离放大器isolation amplifier对数放大器log amplifier反对数放大器antilog amplifier反馈通道feedback path反向漏电流reverse leakage current相位phase相移phase shift锁相环phase-locked loop(PLL)锁相环相位监测器PLL phase detector和频sum frequency差频difference frequency波形发生电路振荡器oscillatorRC振荡器RC oscillatorLC振荡器LC oscillator正弦波振荡器sinusoidal oscillator三角波发生器triangular wave generator方波发生器square wave generator幅度magnitude电平level饱和输出电平(电压)saturated output level功率放大器功率放大器power amplifier交越失真cross-over distortion甲类功率放大器class A power amplifier乙类推挽功率放大器class B push-pull power amplifier OTL功率放大器output transformerless power amplifier OCL功率放大器output capacitorless power amplifier直流稳压电源半波整流full-wave rectifier全波整流half-wave rectifier电感滤波器inductor filter电容滤波器capacitor filter串联型稳压电源series (voltage) regulator开关型稳压电源switching (voltage) regulator集成稳压器IC (voltage) regulator晶闸管及可控整流电路晶闸管thyristor单结晶体管unijunction transistor(UJT)可控整流controlled rectifier可控硅silicon-controlled rectifier峰点peak point谷点valley point控制角controlling angle导通角turn-on angle门电路与逻辑代数二进制binary二进制数binary number十进制decimal十六进制hexadecimal二-十进制binary coded decimal (BCD)门电路gate三态门tri-state gate与门AND gate或门OR gate非门NOT gate与非门NAND gate或非门NOR gate异或门exclusive-OR gate反相器inverter布尔代数Boolean algebra真值表truth table卡诺图the Karnaugh map逻辑函数logic逻辑表达式logic expression组合逻辑电路组合逻辑电路combination logic circuit译码器decoder编码器coder比较器comparator半加器half-adder全加器full-adder七段显示器seven-segment display时序逻辑电路时序逻辑电路sequential logic circuitR-S 触发器R-S flip-flopD触发器D flip-flopJ-K触发器J-K flip-flop主从型触发器master-slave flip-flop置位set复位reset直接置位端direct-set terminal直接复位端direct-reset terminal寄存器register移位寄存器shift register双向移位寄存器bidirectional shift register 计数器counter同步计数器synchronous counter异步计数器asynchronous counter加法计数器adding counter减法计数器subtracting counter定时器timer清除(清0)clear载入load时钟脉冲clock pulse触发脉冲trigger pulse上升沿positive edge下降沿negative edge时序图timing diagram波形图waveform脉冲波形的产生与整形单稳态触发器monostable flip-flop双稳态触发器bistable flip-flop无稳态振荡器astable oscillator晶体crystal555定时器555 timer模拟信号与数字信号的相互转换模拟信号analog signal数字信号digital signalAD转换器analog -digital converter (ADC)DA转换器digital-analog converter (DAC)半导体存储器只读存储器read-only memory(ROM)随机存取存储器random-access memory(RAM)可编程ROM programmable ROM(PROM)。
开关电源外文文献翻译(文档含中英文对照即英文原文和中文翻译)外文:Switched-mode power supplyA switched-mode power supply (also switching-mode power supply, SMPS, or simply switcher) is an electronic power supply unit (PSU) that incorporates a switching regulator. While a linear regulator maintains the desired output voltage by dissipating excess power in a pass power transistor, the switched-mode power supply switches a power transistor between saturation (full on) and cutoff (completely off) with a variable duty cycle whose average is the desired output voltage. It switches at a much-higher frequency (tens to hundreds of kHz) than that of the AC line (mains), which means that the transformer that it feeds can be much smaller than one connected directly to the line/mains. Switching creates a rectangular waveform that typically goes to the primary of the transformer; typically several secondaries feed rectifiers, series inductors, and filter capacitors to provide various DC outputs with low ripple.The main advantage of this method is greater efficiency because the switching transistor dissipates little power in the saturated state and the off state compared to the semiconducting state (active region). Other advantages include smaller size and lighter weight (from the elimination of low frequency transformers which have a high weight) and lower heat generation due to higher efficiency. Disadvantages include greater complexity, the generation of high amplitude, high frequency energy that the low-pass filter must block to avoid electromagnetic interference (EMI), and a ripple voltage at the switching frequency and the harmonic frequencies thereof.A note about terminologyAlthough the term "power supply" has been in use since radios were first powered from the line/mains, that does not mean that it is a source of power, in the sense that a battery provides power. It is simply a device that (usually) accepts commercial AC power and provides one or more DC outputs. It would be more correctly referred to as a power converter, but long usage has established the term. ClassificationSMPS can be classified into four types according to the input and output waveforms: AC in, DC out: rectifier, off-line converter input stageDC in, DC out: voltage converter, or current converter, or DC to DC converterAC in, AC out: frequency changer, cycloconverter, transformerDC in, AC out: inverterInput rectifier stageIf the SMPS has an AC input, then the first stage is to convert the input to DC. This is called rectification. The rectifier circuit can be configured as a voltage doubler by the addition of a switch operated either manually or automatically. This is a feature of larger supplies to permit operation from nominally 120 volt or 240 volt supplies. The rectifier produces an unregulated DC voltage which is then sent to a large filter capacitor. The current drawn from the mains supply by this rectifier circuit occurs in short pulses around the AC voltage peaks. These pulses have significant high frequency energy which reduces the power factor. Special control techniques can be employed by the following SMPS to force the average input current to follow the sinusoidal shape of the AC input voltage thus the designer should try correcting the power factor. An SMPS with a DC input does not require this stage. An SMPS designed for AC input can often be run from a DC supply (for 230V AC this would be 330V DC), as the DC passes through the rectifier stage unchanged. It's howeveradvisable to consult the manual before trying this, though most supplies are quite capable of such operation even though nothing is mentioned in the documentation. However, this type of use may be harmful to the rectifier stage as it will only utilize half of diodes in the rectifier for the full load. This may result in overheating of these components, and cause them to fail prematurely.If an input range switch is used, the rectifier stage is usually configured to operate as a voltage doubler when operating on the low voltage (~120 V AC) range and as a straight rectifier when operating on the high voltage (~240 V AC) range. If an input range switch is not used, then a full-wave rectifier is usually used and the downstream inverter stage is simply designed to be flexible enough to accept the wide range of dc voltages that will be produced by the rectifier stage. In higher-power SMPSs, some form of automatic range switching may be used.Inverter stageThe inverter stage converts DC, whether directly from the input or from the rectifier stage described above, to AC by running it through a power oscillator, whose output transformer is very small with few windings at a frequency of tens or hundreds of kilohertz (kHz). The frequency is usually chosen to be above 20 kHz, to make it inaudible to humans. The output voltage is optically coupled to the input and thus very tightly controlled. The switching is implemented as a multistage (to achieve high gain) MOSFET amplifier. MOSFETs are a type of transistor with a low on-resistance and a high current-handling capacity. Since only the last stage has a large duty cycle, previous stages can be implemented by bipolar transistors leading to roughly the same efficiency. The second last stage needs to be of a complementary design, where one transistor charges the last MOSFET and another one discharges the MOSFET. A design using a resistor would run idle most of the time and reduce efficiency. All earlier stages do not weight into efficiency because power decreases by a factor of 10 for every stage (going backwards) and thus the earlier stages are responsible for at most 1% of the efficiency. This section refers to the block marked Chopper in the block diagram.V oltage converter and output rectifierIf the output is required to be isolated from the input, as is usually the case in mains power supplies, the inverted AC is used to drive the primary winding of a high-frequency transformer. This converts the voltage up or down to the required output level on its secondary winding. The output transformer in the block diagramserves this purpose.If a DC output is required, the AC output from the transformer is rectified. For output voltages above ten volts or so, ordinary silicon diodes are commonly used. For lower voltages, Schottky diodes are commonly used as the rectifier elements; they have the advantages of faster recovery times than silicon diodes (allowing low-loss operation at higher frequencies) and a lower voltage drop when conducting. For even lower output voltages, MOSFETs may be used as synchronous rectifiers; compared to Schottky diodes, these have even lower conducting state voltage drops.The rectified output is then smoothed by a filter consisting of inductors and capacitors. For higher switching frequencies, components with lower capacitance and inductance are needed.Simpler, non-isolated power supplies contain an inductor instead of a transformer. This type includes boost converters, buck converters, and the so called buck-boost converters. These belong to the simplest class of single input, single output converters which utilize one inductor and one active switch. The buck converter reduces the input voltage in direct proportion to the ratio of conductive time to the total switching period, called the duty cycle. For example an ideal buck converter with a 10 V input operating at a 50% duty cycle will produce an average output voltage of 5 V. A feedback control loop is employed to regulate the output voltage by varying the duty cycle to compensate for variations in input voltage. The output voltage of a boost converter is always greater than the input voltage and the buck-boost output voltage is inverted but can be greater than, equal to, or less than the magnitude of its input voltage. There are many variations and extensions to this class of converters but these three form the basis of almost all isolated and non-isolated DC to DC converters. By adding a second inductor the Ćuk and SEPIC converters can be implemented, or, by adding additional active switches, various bridge converters can be realised.Other types of SMPSs use a capacitor-diode voltage multiplier instead of inductors and transformers. These are mostly used for generating high voltages at low currents (Cockcroft-Walton generator). The low voltage variant is called charge pump. RegulationA feedback circuit monitors the output voltage and compares it with a reference voltage, which is set manually or electronically to the desired output. If there is an error in the output voltage, the feedback circuit compensates by adjusting the timing with which the MOSFETs are switched on and off. This part of the power supply is called the switching regulator. The Chopper controller shown in the block diagramserves this purpose. Depending on design/safety requirements, the controller may or may not contain an isolation mechanism (such as opto-couplers) to isolate it from the DC output. Switching supplies in computers, TVs and VCRs have these opto-couplers to tightly control the output voltage.Open-loop regulators do not have a feedback circuit. Instead, they rely on feeding a constant voltage to the input of the transformer or inductor, and assume that the output will be correct. Regulated designs compensate for the parasitic capacitance of the transformer or coil. Monopolar designs also compensate for the magnetic hysteresis of the core.The feedback circuit needs power to run before it can generate power, so an additional non-switching power-supply for stand-by is added.Transformer designSMPS transformers run at high frequency. Most of the cost savings (and space savings) in off-line power supplies come from the fact that a high frequency transformer is much smaller than the 50/60 Hz transformers formerly used.There are several differences in the design of transformers for 50 Hz vs 500 kHz. Firstly a low frequency transformer usually transfers energy through its core (soft iron), while the (usually ferrite) core of a high frequency transformer limits leakage. Since the waveforms in a SMPS are generally high speed (PWM square waves), the wiring must be capable of supporting high harmonics of the base frequency due to the skin effect, which is a major source of power loss.Power factorSimple off-line switched mode power supplies incorporate a simple full wave rectifier connected to a large energy storing capacitor. Such SMPSs draw current from the AC line in short pulses when the mains instantaneous voltage exceeds the voltage across this capacitor. During the remaining portion of the AC cycle the capacitor provides energy to the power supply.As a result, the input current of such basic switched mode power supplies has high harmonic content and relatively low power factor. This creates extra load on utility lines, increases heating of the utility transformers and standard AC electric motors, and may cause stability problems in some applications such as in emergency generator systems or aircraft generators. Harmonics can be removed through the use of filter banks but the filtering is expensive, and the power utility may require a business with a very low power factor to purchase and install the filtering onsite.In 2001 the European Union put into effect the standard IEC/EN61000-3-2 to set limits on the harmonics of the AC input current up to the 40th harmonic for equipment above 75 W. The standard defines four classes of equipment depending on its type and current waveform. The most rigorous limits (class D) are established for personal computers, computer monitors, and TV receivers. In order to comply with these requirements modern switched-mode power supplies normally include an additional power factor correction (PFC) stage.Putting a current regulated boost chopper stage after the off-line rectifier (to charge the storage capacitor) can help correct the power factor, but increases the complexity (and cost).Quasiresonant ZCS/ZVSA quasiresonant ZCS/ZVS switch (Zero Current/Zero V oltage) is a design where "each switch cycle delivers a quantized 'packet' of energy to the converter output, and switch turn-on and turn-off occurs at zero current and voltage, resulting in an essentially lossless switch."EfficiencyHigher input voltage and synchronous rectification mode makes the conversion process more efficient. Higher switch frequency allows component size to be shrunk, but suffer from radio frequency (RF) properties on the other hand. The power consumption of the controller also has to be taken into account.ApplicationsSwitched-mode PSUs in domestic products such as personal computers often have universal inputs, meaning that they can accept power from most mains supplies throughout the world, with rated frequencies from 50 Hz to 60 Hz and voltages from 100 V to 240 V (although a manual voltage range switch may be required). In practice they will operate from a much wider frequency range and often from a DC supply as well. In 2006, at an Intel Developers Forum, Google engineers proposed the use of a single 12 V supply inside PCs, due to the high efficiency of switch mode supplies directly on the PCB.Most modern desktop and laptop computers already have a DC-DC converter on the motherboard, to step down the voltage from the PSU or the battery to the CPU core voltage, as low as 0.8 V for a low voltage CPU to 1.2-1.5 V for a desktop CPU as of 2007. Most laptop computers also have a DC-AC inverter to step up the voltage from the battery to drive the backlight, typically around 1000 Vrms.Certain applications, such as in automobile industry where ordinary cars often use 12 V DC and in some industrial settings, DC supply is chosen to avoid hum and interference and ease the integration of capacitors and batteries used to buffer the voltage. Most small aircraft use 28 V DC, but larger aircraft like Boeing-747 often use up to 90 kV A 3-phase at 200 V AC 400 Hz, though they often have a DC bus as well. Even fighter planes like F-16 use 400 Hz power. The MD-81 airplane has an 115/200 V 400 Hz AC and 28 V DC power system generated by three 40 kV A AC generators. Helicopters also use the 28 V DC system. Some submarines like the Soviet Alfa class submarine utilized two synchronous generators providing a variable three-phase current, 2 x 1500 kW, 400 V, 400 Hz. The space shuttle uses three fuel cells generating 30 - 36 V DC. Some is converted into 400 Hz AC power and 28 V DC power. The International Space Station uses 120 V DC power. Larger trucks uses 24 V DC.See also: Avionics, Airplane ground supportIn the case of TV sets, for example, one can test the excellent regulation of the power supply by using a variac. For example, in some models made by Philips, the power supply starts when the voltage reaches around 90 volts. From there, one can change the voltage with the variac, and go as low as 40 volts and as high as 260 (known such case that voltage was 360), and the image will show absolutely no alterations.TerminologyThe term switchmode was widely used until Motorola trademarked SWITCHMODE(TM), for products aimed at the switching-mode power supply market, and started to enforce their trademark.翻译:开关模式电源开关模式电源(也开关式电源,开关电源,或只是交换机)是一种电子电源供应器(电源),包含了开关稳压器。
Switching Power SupplySwitching power supply is a voltage conversion circuit, the main work is the step-up and step-down, are widely used in modern electronic products. Always work because the switching transistor in the "on" and "off" state, so called switching power supply. Switching power supply in real terms is an oscillator circuit, the conversion of electrical energy not only used in power circuit, the circuit in other applications are also common, such as LCD backlight circuits, such as fluorescent lamps. Switch the source compared with the transformer high efficiency, good stability, small size and other advantages, disadvantages is the relatively small power, and high-frequency interference on the circuit, circuit complexity, such as easy maintenance.Talking about switching power supply before you familiar with the feedback oscillator circuit transformer, can produce a regular pulse current or voltage of the circuit is called oscillation circuit, transformer feedback oscillator circuit is able to meet these conditions the circuit; it in the basic amplifier circuit with a feedback loop composed of C2, L1 election to form a parallel resonant frequency circuit, the instantaneous power in the circuit turn-VT, this time in the C2, L1, composed of parallel resonant circuits have a very rich harmonic, when the plus parallel resonance frequency and the natural frequency of the same circuit, the circuit to enter a state of oscillation, and VT through L3 feedback to further enlarge the base, and ultimately the formation of a regular pulse current or voltage output to the load RL. Switching power supply is around the transformer and the feedback oscillator circuit design, but the basis of the original increase in the number of protection and control circuits, analysis of our oscillation circuit can be used to analyze the method of switching power supply.Switching Power Supply vibration by way of sub-swing can be dividedinto self-excited and it excited the two, since there is no need for plus-excited self-oscillation signal source, since the excitation can see it as a feedback oscillator circuit transformer, and it is excited is totally dependent on the outside to maintain the oscillation, in the practical application of self-excitation of a comprehensive range of applications. According to the structure of incentives signal classification; can be divided into pulse-width-modulated pulse amplitude modulation and two pulse-width-modulated signal to control the width, that is, frequency, pulse amplitude modulation control signal of the magnitude of the role of the two the same so that oscillation frequency is maintained at within a certain range, to the effect of voltage stability. Winding transformer can be divided into three types in general, a group involved in the primary winding of the oscillation, a group is to maintain the oscillation of the feedback winding, there is a group of the load windings. Household appliances used in switching power supply,after the AC to 220V bridge rectifier, converted into about 300V DC, filter into the transformer is added after the switch to high-frequency oscillations of the collector, feedback winding back to the base to maintain the oscillation circuit, load sensor windings of the electrical signal, by rectification, filtering, the DC voltage regulator has been to provide power to the load. Winding in the provision of electric power load, but also take up the capacity of voltage stability, the theory is then a circuit voltage output voltage sampling devices to monitor the output voltage changes, timely feedback to adjust the oscillation frequency oscillator circuit to achieve the voltage stability The purpose of the circuit in order to avoid interference, the feedback voltage to the oscillator circuit will be isolated optocoupler. Most switches have a standby power circuit, switching power supply in standby mode still oscillating, but the frequency of normal working hours than lower.Some switching power supply are complex, numerous components, many protection and control circuit, in the absence of technical support, maintenance is a headache with the matter. I face this kind of situation is, first of all, I will find the switch and its participation in the external oscillation circuit, it separated from the circuit to see if it met the conditions for oscillation, such as detection bias and whether it is normal, whether positive feedback failure, as well as its own switches, switching power supply has very large protection, after exclusion of the prosecution and load control and protection circuit.the control circuit while output from the sample, with the set standards, then controlled inverter, change its frequency or pulse width output achieve stability, on the other hand, according to test data provided by the circuit by circuit protection identification, Control circuit for the unit for various protection measures.SMPS developments and trends in the United States in 1955 Roje (GH.Roger) invention of the self-excited oscillation push redeem transistor single transformer DC converters, high-frequency conversion is the beginning of control circuit, 1957 United States investigation tournament (Jen Sen) since the invention of the push-pull double Flyback transformers, 1964 American scientists proposes to abolish the frequency transformer series switching power supply scenario, This power to the right size and weight of the decline was a fundamental way. To the 1969 high-power silicon transistor because the pressure increase diode reverse recovery time shortened, and other components improve, and finally turned into a 25 kHz switching power supply.Currently, switching power supply to small, Light volume and the characteristics of high efficiency has been widely used in electronic computer-driven variety of terminal equipment, Communications equipment almost all electronic equipment, the electronic information industryindispensable to the rapid development of a power mode. Currently the market for sale in the switching power supply using bipolar transistors made of 100kHz. use made of 500kHz MOS power, though practical, but its frequency to be further enhanced. To improve the switching frequency, it is necessary to reduce the switching loss, and to reduce the switching loss, you need to have high-speed switching devices. However, the switching speed, will be affected by the circuit inductance and capacitance diode or stored charge arising from the impact of the surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Among them, with the switch to prevent Kai-closed by the voltage surge, it is R-C or L-C Composite bumpers, and the storage charge by the diode current surge caused by the use made of amorphous cores such as magnetic bumper. However, the high frequency of 1 MHz and above, using resonant circuit, Switch to enable the voltage or current through the switch was a sine, which could reduce the switching loss, This can also control the surge occurred. Switches such as resonant mode switching. Currently such SMPS of very active, because this means no significant increase switching speed can theoretically put switching loss fall to zero. and the noise is small, is expected to become high-frequency switching power supply of one of the main ways. At present, many countries in the world are working on several trillion Hz converter practical research.开关电源开关电源是一种电压转换电路,主要的工作内容是升压和降压,广泛应用于现代电子产品。
1 DC Switching Power Supply Protection Technology Abstract: The DC switching power supply protection system, protection system design
principles and machine protection measures, an analysis of switching power supply in the range of protected characteristics and its design methodology,introduced a number of practical protection circuit. Keywords: switching power supply protection circuit system design
1、Introduction DC switching regulator used in the price of more expensive high-power switching devices, the control circuit is also more complex, In addition, the load switching regulators are generally used a large number of highly integrated electronic systems installed devices. Transistors and integrated device tolerance electricity, less heat shocks. Switching Regulators therefore should take into account the protection of voltage regulators and load their own safety. Many different types of circuit protection, polarity protection, introduced here, the program protection, over-current protection, over-voltage protection, under-voltage protection and over-temperature protection circuit. Usually chosen to be some combination of protection, constitutes a complete protection system. 2、polarity protection DC switching regulator input are generally not regulated DC power supply. Operating errors or accidents as a result of the situation will take its wrong polarity, switching power supply will be damaged. Polarity protection purposes, is to make the switching regulator only when the correct polarity is not connected to DC power supply regulator to work at. Connecting a single device can achieve power polarity protection. Since the diode D to flow through switching regulator input total current, this circuit applied in a low-power switching regulator more suitable. Power in the larger occasion, while the polarity protection circuit as a procedure to protect a link, save the power required for polarity protection diodes, power consumption will be reduced. In order to easy to operate, make it easier to identify the correct polarity or not, collect the next light. 3、procedures to protect Switching power supply circuit is rather complicated, basically can be divided into low-power and high-power part of the control part of the switch. Switch is a high-power 仇有年:宽输入电压高频开关电源的设计 2 transistors, for the protection of the transistor switch is turned on or off power safety, we must first modulator, amplifier and other low-power control circuit. To this end, the boot to ensure the correct procedures. Switching Regulators generally take the input of a small inductor, the input filter capacitor. Moment in the boot, filter capacitor will flow a lot of surge current, the surge current can be several times more than the normal input current. Such a large surge current may contact the general power switch or relay contact melting, and the input fuse fuse. In addition, the capacitor surge current will damage to shorten the life span of premature damage. To this end, the boot should be access to a current limiting resistor, through the current limiting resistor to capacitor charging. In order not to make the current limiting resistor excessive power consumption, thus affecting the normal switching regulator, and the transient process in the boot after a short period then automatically relays it to DC power supply directly to the switching regulator power supply. This circuit switching regulator called a "soft start" circuit. Switching regulator control circuit of the logic components required or op-amp auxiliary power supply. To this end, the auxiliary power supply must be in the switch circuit. This control circuit can be used to ensure the boot. Normal boot process is: to identify the polarity of input power, voltage protection procedures → boot → auxiliary power supply circuit and through current limiting resistor R of the switching regulator input capacitor C → charge modulation switching regulator circuit, → short-circuit current limiting resistor stability switching regulator. In the switching regulator, the machines just because the output capacitance, and charge to the rated output voltage value of the need for a certain period of time. During this time, sampling the output amplifier with low input voltage sampling, closed-loop regulation characteristics of the system will force the switching of the transistor conduction time lengthened, so that switching transistor during this period will tend to continuous conduction, and easily damaged. To this end, the requirements of this paragraph in the boot time, the switch to switch the output modulation circuit transistor base drive signal of the pulse width modulation, can guarantee the switching transistor by the cut-off switches are becoming more and more normal state, therefore the protection of the setting up of a boot to tie in with the soft start. 4、over-current protection When the load short-circuit, overload control circuit failure or unforeseen