开关电源文献11

1.开关电源研究的背景及意义现实生活中常用的电源，可以分为发出电能的电源和变换电能的电源两大类。

我们把输人和输出都是电能的电源称之为变换电能的电源。

开关电源就是属于变换电能的电源，此种电源就是电路中的电力电子器件工作在开关状态的电源。

开关电源的前身是线性稳压电源。

在我们生活中，大多数电子装置、电气控制设备的工作电源是直流电源。

在开关电源出现之前，这些装置的工作电源都采用线性稳压电源。

在20世纪50年代，美国宇航局以小型化、重量轻为目标,为搭载火箭而开发了开关电源。

在半个多世纪的电力电子技术发展历程中,开关电源因具有体积小、重量轻、效率高、发热量低、性能稳定等优点而逐渐取代传统技术制造的相控稳压电源,并广泛应用于电子整机设备中。

在现代社会,电子信息设备与人们的生活、工作的关系越来越密切,而所有的电子设备都离不开电源。

高速发展的计算机技术带领人类进入了信息社会,同时也促进了电源技术的迅速发展。

电源技术的精髓是电能变换,即利用电能变换技术,将市电或电池等一次电源变换成适用于各种用电对象的二次电源。

开关电源技术属于电力电子技术,它运用功率变换器进行电能变换。

经过变换的电能,可以满足各种用电需求。

由于其高效节能可带来巨大经济效益,因而引起社会各方面的重视而得到迅速推广。

2.国内外研究现状及发展趋势开关电源真正的发展是从70年代开始的,在此期间系统的电力电子理论的确立。

电力电子理论为开关电源的发展提供了一个良好而必需的基础。

但在产品应用的初期,存在开关频率低(20kHz以下)、功率密度比较低、可靠性较差的缺点。

因此开关电源主要的发展方向,是针对上述缺点不断加以改善。

大功率场效应管(MOSFET)及绝缘栅晶体管(IGBT)等器材的出现为高频和大功率变换器提供了极有利的条件。

新的器件和新的拓扑理论的出现使得开关电源技术日趋可靠、成熟、经济、适用。

开关电源目前的发展,主要朝着更高的功能密度和变换效率及更好的动态特性；更好的环保性能；智能化与高可靠性；更广泛的应用等方向发展。

反激式开关电源（毕业论⽂）随着电⼒电⼦技术的发展，开关电源的应⽤越来越⼴泛。

反激式开关电源以其设计简单，体积⼩巧等优势，⼴泛应⽤于⼩功率场合。

开关电源以其⼩型、轻量和⾼效率的特点，被⼴泛地应⽤于各种电⽓设备和系统中，其性能的优劣直接关系到整个系统功能的实现。

开关稳压电源有多种类型，其中单端反激式开关电源由于具有线路简单，所需要的元器件少，能够提供多路隔离输出等优点⽽⼴泛应⽤于⼩功率电源领域。

传统的反激式开关电源⼀般由PWM控制芯⽚(如UC3842)和功率开关管(频率较⾼时⼀般使⽤MOSFET)组成，PWM芯⽚控制环路设计复杂，容易造成系统⼯作不稳定，功率开关管有时需要外加驱动电路。

⾼效率与⼩型化在⼀定程度上是互相限制的，因为实现⾼效率会要求电路有相当的复杂度，⼤量的器件对⼩型化⼗分不利。

在开关电源设计初期，采⽤的都是分⽴元件，集成度很低，⼤部分电路只能在PCB版上实现，极⼤的限制了⼩型化实现的可能。

⽽且⼤量器件暴露在外，也影响了系统的稳定性。

采⽤近年来，为了实现更⾼的效率和更⼩的体积，开关电源的⼯作频率有了很⼤的提⾼。

⾼⼯作频率能够减⼩外围电感和电容的⼤⼩，从⽽减少系统的体积。

另外，反激变压器的设计也是⼀个难点，其往往导致电源设计周期延长。

随着PI公司⽣产的以TOPSwitch为代表的新⼀代单⽚开关电源的问世，以上诸多问题都得到了很好的解决。

应⽤TOPSwitch-HX设计开关电源，不仅器件更少，结构更简单，发热量更少，⼯作更可靠，采⽤该系列芯⽚已成为⼀种⾼效的反激式开关电源设计⽅案。

关键词：TOPSwitch-HX 反激式变换器⾼频变压器开关电源.第⼀章绪论 (1)⼀、反击式开关电源的背景 (1)⼆、反击式开关电源现状与发展趋势 (2)三、本课题选题意义及所做⼯作 (2)第⼆章反击式开关电源简介 (3)⼀、开关电源的分类 (3)⼆、反击式开关电源的原理 (4)第三章⾼效反激式开关电源系统设计 (5)⼀、提⾼效率的⽅法 (5)⼆、⾼效反激式开关电源的系统设计原理图 (6)三、各个⼦电路的分析设计 (7)第四章反激式开关电源元件选择及其参数 (8)⼀、Topswitch-HX 系列元件简介 (8)⼆、提⾼开关电源效率元件选取⽅法 (10)三、主要参数的计算 (11)第五章设计总结与展望 (13)参考⽂献 (14)致谢 (15)附录 (16)第⼀章绪论⼀、反激式开关电源的背景开关电源的前⾝是线性稳压电源。

文献综述电气工程及自动化开关电源研究综述摘要：文章对开关电源做了较为全面的介绍。

概括了开关电源的背景知识，定义，应用以及较为详细的分类情况。

然后对开关电源的分类以及发展的走势进行了展望。

关键词：开关电源控制电路电路设计1.引言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。

任何电子设备都离不开可靠的电源，它们对电源的要求也越来越高。

电子设备的小型化和低成本使电源以轻、薄、小和高效率为发展方向。

在近半个多世纪的发展过程中，开关电源因具有体积小、重量轻、效率高、发热量低、性能稳定等优点而取代传统技术设计制造的连续工作的线性电源，并广泛应用于电子、电气设备中。

20世纪80年代，计算机全面实现了开关电源化，率先完成了计算机的电源换代。

20世纪90年代，开关电源在电子、电气设备以及家电领域得到了广泛的应用，开关电源技术进入快速发展期。

[1]开关电源是利用现代电力电子技术，控制开关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MOSFET构成。

[4]开关电源的工作过程相当容易理解，在线性电源中，让功率晶体管工作在线性模式，与线形电源不同的是，PWM开关电源是让功率晶体管工作在导通和关断的状态，在这两种状态中，加在功率晶体管上的伏-安乘积是很小的（在导通时，电压低，电流大；关断时，电压高，电流小）功率器件上的伏安乘积就是功率半导体器件上所产生的损耗。

[2-3]与线性电源相比，PWM开关电源更为效的工作过程是通过“斩波”，即把输入的直流电压斩成幅值等于输入电压幅值的脉冲电压来实现的。

脉冲的占空比由开关电源的控制器来调节。

一旦输入电压被斩成交流方波，其幅值就可以通过变压器来升高或降低。

通过增加变压器的二次绕组数就可以增加输出的电压组数。

最后这些交流波形经过整流滤波后就得到直流输出电压。

[8]开关电源可分为AC/DC和DC/DC两大类，也有AC/AC DC/AC 如逆变器DC/DC变换器现已实现模块化，且设计技术及生产工艺在国内外均已成熟和标准化，并已得到用户的认可，但AC/DC的模块化，因其自身的特性使得在模块化的进程中，遇到较为复杂的技术和工艺制造问题。

开关电源与电子技术的飞速发展,电子系统的应用领域越来越广泛,电子设备,有越来越多的人工作以电子设备、生活越来越密切的关系。

任何电子设备都离不开可靠供电电源的需求,他们也越来越高。

电子设备的小型化、低成本的光的力量又瘦,小而高效的为发展方向。

传统的晶体管稳压电源是系列调整连续控制线性稳压电源。

这种传统的稳压电源的技术更加成熟,已经有大量的综合线性稳压电源模块,有稳定的性能好、输出电压波动小、运行可靠等。

但通常需要体积大且沉重的工频变压器和体积和重量是大的过滤器。

在1950年代,美国国家航空和宇宙航行局的小型化、轻重量为目标,为火箭携带开关电源的发展。

在近半个世纪的发展过程中,开关电源因其体积小、重量轻、效率高,适用范围广,电压的优点在电子、控制、计算机等许多领域的电子设备已得到广泛应用。

在1980年代,计算机是由所有开关电源的,第一个完整的计算机发电。

整个1990年代,开关电源在电子、电器、家用电器领域得到广泛、开关电源技术进入快速发展。

此外,大规模集成电路技术,和快速发展,开关电源有了质的飞跃,提高了高频大功率产品的、小型化、模块化的潮流。

电源开关管、PWM控制器和高频变压器是不可或缺的组成部分,开关电源。

传统的开关电源的一般均采用高频大功率开关管的划分及各销,如利用PWM(脉宽调制)集成控制器UC3842 + MOSFET是国内小功率开关电源的设计方法,更流行。

自1970年代以来,出现在许多功能完全集成控制电路、开关电源电路越来越简化,工作频率的不断提高,提高效率,为电力小型化提供更为广阔的发展前景。

三结束离线脉冲宽度调制单片机顶部(三个交换线)将终端时,电源开关MOSFET PWM控制器包在一起,已经成为国际关系的主流,开关电源IC发展。

采用集成电路设计上的开关电源开关,可使电路简单、体积进一步缩小,成本也明显降低单片开关电源有单片集成,最简外围电路,最好的性能指标、没有工作频率变压器能构成一个重要的优势开关电源等PI(以)。

开关稳压电源设计与实现摘要：本文主要介绍开关电源的概述，开关电源的类型,开关电源的发展方向及类型,单片开关电源的原理及应用。

本设计主要是利用3端单片开关电源芯片TOP223Y,进行小功率的开关稳压电源的设计与制作，主要是用开关电源芯片TOP223Y的脉宽调制技术控制开关管,来调制输出电压，以达到稳定输出的目的,最终设计的电路，主要有输入整流滤波、TOP223Y脉宽调制、高频变压器、电压反馈整流滤波、输出整流滤波五部分组成。

关键词：开关电源/TOP223Y/脉宽调制技术一、引言随着电子设备的高速发展, 电子设备与人们的工作、生活的关系日益密切. 任何电子设备都离不开可靠的电源, 他们对电源的要求也越来越高。

电子设备的小型化和低成本化使电源以轻、薄、小和高效率为发展方向。

20世纪80年代，计算机全面实现了开关电源化, 率先完成计算机的电源换代。

20世纪90年代, 开关电源在电子、电器设备、家电领域得到了广泛应用,开关电源技术进入快速发展时期。

开关电源集成电路具有高集成度、高性价比、最简外围电路、最佳性能指标、能构成高效率无工频变压器的隔离式开关电源等优点。

它于90年代中、后期相继问世后,便显示出强大的生命力,目前它成为国际上开发中、小功率开关电源、精密开关电源及电源模块的优选集成电路。

由它构成的开关电源,在成本上与同等功率的线性稳压电源相当，而电源效率显著提高，体积和重量则大为减小。

这就为新型开关电源的推广与普及，创造了良好条件。

开关电源技术属于电力电子技术，它运用功率变换器进行电能变换，经过变换电能,可以满足各种用电要求。

由于其高效节能可带来巨大经济效益，因而引起社会各方面的重视而得到迅速推广。

随着ＰＷＭ技术的不断发展和完善,开关电源得到了广泛的应用,以往开关电源的设计通常采用控制电路与功率管相分离的拓扑结构,但这种方案存在成本高、系统可靠性低等问题。

美国功率集成公司。

Power Integration Inc开发的TOP Switch系列新型智能高频开关电源集成芯片解决了这些问题，该系列芯片将自启动电路、功率开关管、ＰＷＭ控制电路及保护电路等集成在一起，从而提高了电源的效率，简化了开关电源的设计和新产品的开发，使开关电源发展到一个新的时代。

外文文献：Switching Power Supply DesignSwitching power supply work in high frequency, high pulse state, are analog circuits in a rather special kind. Cloth boards to follow the principle of high-frequency circuit wiring.First, layout:Pulse voltage connection as short as possible, including input switch connected to the transformer, output transformer to the rectifier tube cable. Pulse current loop as small as possible such as the input filter capacitor is returned to the transformer to the switch capacitor negative. Some out-ended output transformers are the output rectifier to the output capacitor back to transformer circuit X capacitor as close as possible to the input switching power supply, input lines should be avoided in parallel with other circuits, should be avoided. Y capacitor should be placed in the chassis ground terminal or FG connectors. A total of touch induction and transformer to maintain a certain distance in order to avoid magnetic coupling. Such as poor handling of feeling in between inductor and transformer plus a shield, over a number of EMC performance for power supply to the greater impact.General the output capacitor can be used the other two a close rectifier output terminal should be close to, can affect the power supply output ripple index, two small capacitor in parallel results should be better than using a large capacitor. Heating devices to maintain a certain distance, and electrolytic capacitors to extend machine life, electrolytic capacitors is the switching power supply bottleneck life, such as transformers, power control, high power resistors and electrolytic to maintain the distance required between the electrolyte leaving space for heat dissipation , conditions permitting, may be placed in the inlet.Control part to pay attention to: Weak signal high impedance circuit connected to sample the feedback loop as short as in the processing as far as possible avoid interference, the current sampling signal circuits, in particular the current control circuit, easy to deal with some unexpected bad The accident, which had some skill,now to 3843 the circuit example shown in Figure (1) Figure 1 better than Yu Figure 2, Figure 2 Zai full time by observing the current waveform oscilloscope Mingxian superimposed spikes, Youyuganrao limited flow ratio design Zhi Dian low, Figure 1 there is no such phenomenon, there are switch drive signal circuit, switch resistance should be close to the switch driver can switch the work to improve the reliability of this and the high DC impedance voltage power MOSFET driver characteristics. Second, routingAlignment of current density: now the majority of electronic circuit board using insulated copper constitute tied. Common PCB copper thickness of 35μm, the alignment value can be obtained in accordance with 1A/mm experience the value of current density, the specific calculations can be found in textbooks. To ensure the alignment principles of mechanical strength should be greater than or equal to the width of 0.3mm (other non-power supply circuit board may be smaller minimum line width). PCB copper thickness of 70μm is also common in switching power supply, then the current density can be higher.Add that, now Changyong circuit board design tool design software generally items such as line width, line spacing, hole size and so dry plate Guo Jin Xing parameters can be set. In the design of circuit boards, design software automatically in accordance with the specifications, can save time, reduce some of the workload and reduce the error rate.Generally higher on the reliability of lines or line density wiring can be used double panel. Characterized by moderate cost, high reliability, to meet most applications.The ranks of some of the power module products are also used plywood, mainly to facilitate integration of power devices such as transformer inductance to optimize wiring, cooling and other power tube. Good consistency with the craft beautiful, transformer cooling good advantage, but its disadvantage is high cost, poor flexibility, only suitable for industrial mass production.Single-sided, the market circulation of almost universal switching power supply using single-sided circuit board, which has the advantage of lower costs in thedesign and production technology are also taken some measures to ensure its performance.Single PCB design today to talk about some experience, as a single panel with low cost, easy-to-manufacture features, the switching power supply circuit has been widely used, because of its side tied only copper, the device's electrical connections, mechanical fixation should rely on the copper layer, the processing must be careful.To ensure good performance of the mechanical structure welding, single-sided pad should be slightly larger to ensure that the copper and substrate tied good focus, and thus will not be shocked when the copper strip, broken off. General welding ring width should be greater than 0.3mm. Pad diameter should be slightly larger than the diameter of the device pins, but not too large, to ensure pin and pad by the solder connection between the shortest distance, plate hole size should not hinder the normal conditions for the degree of investigation, the pad diameter is generally greater than pin diameter 0.1-0.2mm. Multi-pin device to ensure a smooth investigation documents can also be larger.Electrical connection should be as wide as possible, in principle, should be larger than the width of pad diameter, special circumstances should be connected in line with the need to widen the intersection pad (commonly known as Generation tears), to avoid breaking certain conditions, line and pad. Principle of minimum line width should be greater than 0.5mm.Single-board components to be close to the circuit board. Need overhead cooling device to device and circuit board between the pins plus casing, can play a supporting device and increase the dual role of insulation to minimize or avoid external shocks on the pad and the pin junction impact and enhance the firmness of welding. Circuit board supporting the weight of large parts can increase the connection point, can enhance joint strength between the circuit board, such as transformers, power device heat sink.Single-sided welding pins without affecting the surface and the shell spacing of the prior conditions, it can be to stay longer, the advantage of increased strength of welded parts, increase weld area and immediately found a Weld phenomenon. Shearpin long legs, the welding force smaller parts. In Taiwan, the Japanese often use the device pins in the welding area and the circuit board was bent 45 degrees, and then welding process, its reasoning Ibid. Double panel today to talk about the design of some of the issues, in relatively high number of requests, or take the line density of the larger application environments using double-sided PCB, its performance and various indicators of a lot better than a single panel.Two-panel pad as holes have been high intensity metal processing, welding ring smaller than a single panel, the pad hole diameter slightly larger in diameter than pins, as in the welding process solder solution conducive to penetrate through the top hole solder pad to increase the welding reliability. But there is a disadvantage if the hole is too large, wave soldering tin when the jet impact in the lower part of the device may go up, have some flaws.High current handling of alignment, line width in accordance with pre-quote processing, such as the width is not enough to go online in general can be used to increase the thickness of tin plating solution, the method has a good variety of1. Will take the line set to pad property, so that when the circuit board manufacturing solder alignment will not be covered, the whole hot air normally be tin plated.2. In the wiring by placing pads, the pad is set to take in line shape, pay attention to the pad holes set to zero.3. In the solder layer placed on line, this method is the most flexible, but not all PCB manufacturers will understand your intentions, needed captions. Place the line in the solder layer of the site will not coated solder tinning line several methods as above, to note that, if the alignment of a very wide all plated with tin in solder after the solder will bond a lot and distribution is very uneven, affecting appearance. Article tin can be used generally slender width in the 1 ~ 1.5mm, length can be determined according to lines, tin part of the interval 0.5 ~ 1mmDouble-sided circuit board for the layout, the alignment provides a very selective, make wiring more reasonable. On the ground, the power ground and signal ground must be separated, the two to converge in filter capacitors, in order to avoid a large pulsed current through the signal ground connection instability caused by unexpectedfactors, the signal control circuit grounding point as far as possible, a skill, as far as possible the alignment of the non-grounded wiring layer in the same place, the last shop in another layer of earth. Output line through the filter capacitors, the general first, and then to the load, input line must also pass capacitor, to the transformer, the theoretical basis is to ripple through trip filter capacitor.V oltage feedback sampling, in order to avoid high current through the alignment of the feedback voltage on the sampling point must be the most peripheral power output to increase the load effect of target machine.Alignment change from a wiring layer to another wiring layer generally used hole connected, not through the pin pad device to achieve, because the plug in the device may be damaged when the relationship between this connection, there is current in every passage of 1A, at least two through-hole, through hole diameter is greater than the principle of 0.5mm, 0.8mm generally processed ensure reliability.Cooling devices, in some small power supply, the circuit board traces can be and cooling, characterized by the alignment as generous as possible to increase the cooling area is not coated solder, conditions can even be placed over holes, enhanced thermal conductivity .Today to talk about the aluminum plate in the switching power supply application and multilayer printed circuit in the switching power supply applications.Aluminum plate by its own structure, has the following characteristics: very good thermal conductivity, single Mianfu copper, the device can only be placed in tied copper surface, can not open electrical connection hole so as not to place jumper in accordance with a single panel.Aluminum plate is generally placed patch device, switch, the output rectifier heat conduction through the substrate to go out, very low thermal resistance, high reliability can be achieved. Transformer with planar chip structure, but also through substrate cooling, the temperature is lower than the conventional, the same size transformer with a large aluminum plate structure available output power. Aluminum plate jumper bridge approach can be used. Aluminum plate power are generally composed by the two PCB, another one to place the control circuit board, through thephysical connection between the two boards is integrated.As the excellent thermal conductivity of aluminum plate, in a small amount of manual welding more difficult, solder cooling too fast and prone to problems of a simple and practical way of existing, an ironing ordinary iron (preferably temperature regulation function), over and iron for the last, fixed, and temperature to 150 ℃ and above the aluminum plate on the iron, heating time, and then affix the components according to conventional methods and welding, soldering iron temperature is appropriate to the device easy to , is too high when the device may be damaged, or even copper strip aluminum plate, the temperature is too low welding effect is not good, to be flexible.Recent years, with the multi-layer circuit board applications in switching power supply circuit, printed circuit transformer makes it possible, due to multilayer, smaller spacing also can take advantage of Bianya Qi window section, the main circuit board can be re- Add 1-2 formed by the multilayer printed coil to use the window, the purpose of reducing circuit current density, due to adopt printed coil, reducing manual intervention, transformers consistency, surface structure, low leakage inductance, coupling good . Open-type magnetic core, good heat dissipation. Because of its many advantages, is conducive to mass production, it is widely used. But the research and development of large initial investment, not suitable for small-scale health.Switching power supply is divided into, two forms of isolation and non-isolated, isolated here mainly to talk about switching power supply topologies form below, non-specified, are to isolate the power. Isolated power supply in accordance with the structure of different forms, can be divided into two categories: a forward and flyback. Flyback transformer primary side means that when the Vice-edge conduction cut-off, transformer storage. Close of the primary, secondary side conduction, the energy released to the load of work status, general conventional flyback power multiplex, twin-tube is not common. Forward refers to the primary conduction in transformer secondary side while the corresponding output voltage is induced into the load, the direct transfer of energy through the transformer. According to specifications can be divided into conventional forward, including the single-transistor forward, DoubleForward. Half-bridge, bridge circuits are all forward circuit.Forward and flyback circuits have their own characteristics in the process of circuit design to achieve optimal cost-effective, can be applied flexibly. Usually in the low-power flyback can be adopted. Slightly larger forward circuit can use a single tube, medium-power can use Double Forward circuit or half-bridge circuit, low-voltage push-pull circuit, and the half-bridge work in the same state. High power output, generally used bridge circuit, low voltage can be applied push-pull circuit. Flyback power supply because of its simple structure, and to cut the size of a similar size and transformer inductance, the power supply in the medium has been widely applied. Presentation referred to in some flyback power supply can do dozens of watts, output power exceeding 100 watts would be no advantage to them difficult. Under normal circumstances, I think so, but it can not be generalized, PI's TOP chips can do 300 watts, an article describes the flyback power supply can be on the KW, but not seen in kind.Power output and the output voltage level.Flyback power transformer leakage inductance is a critical parameter, because the power needs of the flyback transformer stored energy, to make full use of transformer core, the general must be open in the magnetic circuit air gap, the aim is to change the core hysteresis back line of the slope, so that transformers can withstand the impact of a large pulse current, which is not core into saturation non-linear state, the magnetic circuit in the high reluctance air gap in the state, generated in the magnetic flux leakage is much larger than completely closed magnetic circuit .Transformer coupling between the first pole is the key factor determining the leakage inductance, the coil to be very close as far as possible the first time, the sandwich can be used around the law, but this would increase the distributed capacitance transformer. Use core as core with a long window, can reduce the leakage inductance, such as the use of EE, EF, EER, PQ-based EI type magnetic core effective than good.The duty cycle of flyback power supplies, in principle, the maximum duty cycle of flyback power supply should be less than 0.5, otherwise not easy loopcompensation may be unstable, but there are some exceptions, such as the U.S. PI has introduced the TOP series chip can work under the conditions of duty cycle is greater than 0.5.Duty cycle by the transformer turns ratio to determine former deputy side, I am an anti-shock view is, first determine the reflected voltage (output voltage reflected through the transformer coupling the primary voltage value), reflecting a certain voltage range of voltage increase is duty cycle increases, lower power loss. Reduce the reflected voltage duty cycle decreases, increases power loss. Of course, this is a prerequisite, when the duty cycle increases, it means that the output diode conduction time, in order to maintain output stability, more time will be to ensure that the output capacitor discharge current, the output capacitor will be under even greater high-frequency ripple current erosion, while increasing its heat, which in many circumstances is not allowed.Duty cycle increases, change the transformer turns ratio, transformer leakage inductance will increase, its overall performance change, when the leakage inductance energy large enough, can switch to fully offset the large account space to bring low-loss, no further increase when the meaning of duty, because the leakage inductance may even be too high against the peak voltage breakdown switch. Leakage inductance as large, may make the output ripple, and other electromagnetic indicators deteriorated. When the duty hours, the high RMS current through the switch, transformer primary current rms and lowered the converter efficiency, but can improve the working conditions of the output capacitor to reduce fever. How to determine the transformer reflected voltage (duty cycle)Some netizens said switching power supply feedback loop parameter settings, work status analysis. Since high school mathematics is rather poor, "Automatic Control Theory," almost on the make-up, and for the door is still feeling fear, and now can not write a complete closed-loop system transfer function, zero for the system, the concept of feeling pole vague, see Bode plot is only about to see is a divergence or convergence, so the feedback compensation can not nonsense, but there are a number of recommendations. If you have some mathematical skills, and then have some timeto learn then the University of textbooks, "Principles of Automatic Control" digest look carefully to find out, combined with practical switching power supply circuit, according to the work of state for analysis. Will be harvested, the Forum has a message, "coach feedback loop to study the design, debugging," in which CMG good answer, I think we can reference.Then today, on the duty cycle of flyback power supply (I am concerned about the reflected voltage, consistent with the duty cycle), the duty cycle with the voltage selection switch is related to some early flyback switching power supply using a low pressure tube, such as 600V or 650V AC 220V input power as a switch, perhaps when the production process, high pressure tubes, easy to manufacture, or low-pressure pipes are more reasonable conduction losses and switching characteristics, as this line reflected voltage can not be too high, otherwise the work order to switch the security context of loss of power absorbing circuit is quite impressive.Reflected voltage 600V tube proved not more than 100V, 650V tube reflected voltage not greater than 120V, the leakage inductance voltage spike when the tubes are clamped at 50V 50V working margin. Now that the MOS raise the level of manufacturing process control, flyback power supplies are generally used 700V or 750V or 800-900V the switch. Like this circuit, overvoltage capability against a number of switching transformer reflected voltage can be done a bit higher, the maximum reflected voltage in the 150V is appropriate, to obtain better overall performance.TOP PI's recommendation for the 135V chipset with transient voltage suppression diode clamp. But his evaluation board generally reflected voltage to be lower than the value at around 110V. Both types have their advantages and disadvantages: Category: shortcomings against over-voltage, low duty cycle is small, a large pulse current transformer primary. Advantages: small transformer leakage inductance, electromagnetic radiation and low ripple index higher switch loss, the conversion efficiency is not necessarily lower than the second.The second category: a large number of shortcomings of power loss, a large number of transformer leakage inductance, the ripple worse. Advantages: Some strongagainst over-voltage, large duty cycle, lower transformer losses and efficiency higher.Reflected voltage flyback power supply and a determining factorReflected voltage flyback power supply with a parameter related to that is the output voltage, output voltage, the lower the larger the transformer turns ratio, the greater the transformer leakage inductance, switch to withstand higher voltage breakdown switch is possible to absorb power consumption is higher, has the potential to permanently absorb the circuit power device failure (particularly with transient voltage suppression diode circuits). In the design of low-voltage low-power flyback power output optimization process must be handled with care, its approach has several:1, using a large core of a power level lower leakage inductance, which can improve the low-voltage flyback power conversion efficiency, reduce losses, reduce output ripple and improve multi-output power of the cross regulation in general is common in household appliances with a switch power, such as CD-ROM drive, DVB set-top boxes.2, if the conditions were not increased core, can reduce the reflected voltage, reducing the duty cycle. Reduce the reflected voltage can reduce the leakage inductance but may reduce the power conversion efficiency, which is a contradiction between the two, must have an alternative process to find a suitable point, replace the transformer during the experiment can detect the transformer original side of the anti-peak voltage, peak voltage to minimize the anti-pulse width, and magnitude of the work safety margin increase converter. Generally reflected voltage 110V when appropriate.3, enhance the coupling, reducing losses, the introduction of new technologies, and the routing process, transformers to meet the security specifications will between the primary and secondary side to insulation measures, such as pad tape, plus side air insulation tape. These will affect the performance of transformer leakage inductance, the reality can be used in production around the primary winding secondary wrapping method. Or sub-system with a triple insulated wire wound to remove the insulation between the initial level, can enhance the coupling, even use wide copper winding.The article refers to low voltage output is less than or equal to 5V output, as thistype of small power supply, my experience is that the power output of more than 20W output can use a forward, get the best value for money, of course, this is not the right decision , and personal habits, relationship between the application environment, the next time to talk about the flyback power supply with a magnetic core, magnetic circuit air gap opening some understanding, I hope you receive adequate guidance.Flyback power transformer core magnetization state at work in one way, it needs to open the air gap magnetic circuit, similar to the pulsating direct current sensor. Part of the magnetic coupling through the air gap. Why I understand the principle of open air gap as follows: As the power ferrite also has a similar rectangle of the operating characteristics (hysteresis loop), operating characteristics curve in the Y-axis magnetic induction (B), now the general production process saturation point in 400mT above, the general value in the design of this value should be more appropriate in the 200-300mT, X-axis magnetic field strength (H) the value of current intensity is proportional to the magnetization. Open magnetic circuit air gap equal to the magnetic hysteresis loop to the X axis tilt, in the same magnetic induction intensity, can withstand a greater magnetizing current, equivalent to core store more energy, this energy cut-off switch When spilled into the load through the transformer secondary circuit, flyback power core to open the air gap is twofold. One is to transfer more energy, and the second to prevent the core into saturation.Flyback Power Transformer magnetization state in one way, not only to pass through the magnetic coupling energy, is also responsible for input and output isolation voltage transform multiple roles. Therefore, the treatment gap need to be very careful, the air gap leakage inductance can become too large, increase the hysteresis loss, iron loss, copper loss increases, affecting the power of the whole performance. Air gap is too small has the potential to transformer core saturation, resulting in damage to powerThe so-called flyback power supply is continuous and discontinuous mode transformer working conditions, working in full load condition in the power transformer complete transfer, or incomplete transmission mode. General design of the working environment, conventional flyback power supply should work incontinuous mode, this switch, circuit loss are relatively small, and can reduce the stress of work input and output capacitors, but that there are some exceptions.Requires in particular that: As the characteristics of the flyback power supply is also more suitable for design into a high-voltage power supply, and high-voltage power transformers generally work in discontinuous mode, I understand the need for as high voltage power supply output voltage of the rectifier diodes. Because of the manufacturing process characteristics, high-tension diode, reverse recovery time is long, low speed, the current continuous state, the diode has a positive bias in the recovery, reverse recovery energy loss is very large, is not conducive to converter performance increase, ranging from reduced conversion efficiency, rectifiers, severe fever, weight is even burnt rectifier. As in the intermittent mode, the diode is reverse biased under zero bias, loss can be reduced to a relatively low level. Therefore, high voltage power supply work in discontinuous mode, and the frequency can not be too high.Another type of flyback power supply work in the critical state, the general type of power supply work in FM, or FM-width-modulated dual-mode, a number of low-cost self-excitation power (RCC) is often used this form in order to ensure stable output transformer As the operating frequency, output current or input voltage change, close to the fully loaded transformer is always maintained at between continuous and intermittent, this power is only suitable for small power output, otherwise the handling characteristics of electromagnetic compatibility will be a headache Flyback switching power supply transformer should work in continuous mode, it required relatively large winding inductance, of course, is to some extent continuous, excessive pursuit of absolute continuity is not realistic, may need a great core, very much coil turns, accompanied by a large leakage inductance and distributed capacitance, worth the trouble. So how does this parameter to determine, through repeated practice, and analysis of peer design, I think, in the nominal voltage input, the output reached 50% and 60% transformer from intermittent, continuous state of transition to more appropriate. Or at the highest input voltage state, the full output, the transformer can transition to the continuous state on it.中文译文：开关电源设计开关电源状态，电源工作在高频率，高脉冲的模拟电路的一个比较特殊的一种。

开关电源APFC电路的研究文献综述摘要：功率因数校正技术是提高功率因数，减少谐波的重要手段，成为目前电力电子学领域研究的热点。

本文首先介绍有源功率因数校正技术的发展及研究现状，说明有源功率因数校正的基本原理，对基本变换电路和控制策略进行了比较和分析，在此基础上，提出了本文研究的对象为平均电流控制的Boost型APFC电路。

关键词：功率因数；UC3854BN；Boost PFC；平均电流控制随着电力电子技术的不断进步及社会发展的需要，几乎所有电器设备的电源装置部分都采用开关电源。

开关电源时为计算机，通信和家用电子设备等提供直流电源的一种电力电子装置，具有体积小，效率高，功率密度大等优点，在电源领域中已占据主导地位，获得了越来越广泛的应用，但由此产生的网侧输入功率因素降低以及谐波问题等也日趋严重。

目前，它迫使电力电子技术领域的研究人员要对这类问题给出有效的解决方案。

人们最早是采用电感和电容构成的无源网络来进行功率因素校正的，但采用这种技术的设备体积庞大，对输入电流的谐波和抑制效果也并不十分理想，随着电力半导体器件的发展，开关变换技术突飞猛进，20世纪80年代，有源功率因素校正APFC(Aetive Power Factor Correction)应运而生。

功率因数校正的目的，就是采用一定的控制方法，使电源的输入电流跟踪输入电压，功率因数接近为1[1]。

1．前言1.1国内国外研究现状节能和环境保护是21世纪科技发展的主题之一，针对电磁污染对人们生活环境和供电质量的影响，许多国家和相关的国际组织制定了许多相关标准和颁布了许多相关法令，以限制电子设备的谐波污染和提高用电设备的功率因数。

随着开关电源类电子产品的应用普及，为了改善供电线路的供电质量·提高供电线路的功率因数、保护用电设备、世界上许多国家制定了相应的技术标准，用以限制谐波电流的含量。

例如IEC 555—2、IEC61000-3-2、EN60555-2等标准，它们规定了允许用电电器产生的最大谐波电流。

摘要在阐述BOOST开关电源工作原理的基础上，设计了一个输出电压可调的开关电源电路，针对开关电源设计中所关心的输出电压纹波，开关管场效应的占空比，主要功能器件（开关管、电感、电容、二极管）功率损耗、效率与电感电容取值的关系、效率与电流负载的关系进行了LTspice仿真，并给出了相应的仿真结果，根据仿真的结果及方法可以进一步提高开关电源的效率，关键词：开关电源；Boost变换；LTspice IV。

AbstractA boost converter circuit with sdjustable output voltage is designed on describing zhe principle of switching mode power supply in zhe article.The simulation results are given by LTspice that zhe ripple of output voltage,the swilch duty cycle of switcling FET,the power loss of main function devices(switching FET,inductor,capacitor,and diode),the relationship of efficiency va.values of inductor and capacotor and the relationship of effciency vs.load current which are attended when switch mode power supply designed,the efficiency of switching mode power supply can be further improved according to the simulation measults and ways.Key word:switching mode power supply;boost convvert;LTspice IV.目录1 引言 (3)2 电路的工作状态 (3)3 matlab仿真分析 (4)4系统方案设计 (4)4.1系统方框图 (4)4.2 boost升压电路模型 (4)5 电路参数的计算及元器件选型 (5)5.1 系统要求 (5)5.2 TL494工作原理 (5)5.3 开关频率的计算 (8)5.4 电感值的计算 (8)5.5 二极管选型 (10)6系统总设计原理图 (10)7 设计结果与分析 (11)7.1 测试工具 (11)7.2 比较基准波形图 (11)7.3 TL494输出波形 (11)7.4输出纹波波形 (12)7.5 电感输出波形 (12)7.6 实物图 (13)8实验小结 (14)参考文献 (15)1 引言BOOST 电路又称为升压型电路, 是一种直流- 直流变换电路, 其电路结构如图1 所示。

开关电源设计参考文献
以下是一些关于开关电源设计的参考文献：
《开关电源设计指南》- 谢运祥，朱忠良，等。

人民邮电出版社，2017。

《开关电源原理与设计》- 洪峰，等。

电子工业出版社，2017。

《开关电源技术教程》- 齐殿元，刘冬，等。

化学工业出版社，2016。

《开关电源的设计与实践》- 王文渊，王峰，等。

机械工业出版社，2017。

《开关电源优化设计》- 谢运祥，朱忠良，等。

人民邮电出版社，2017。

以上参考文献涵盖了开关电源设计的各个方面，包括设计指南、原理、技术教程、实践和优化设计等。

这些书籍为从事开关电源设计的人员提供了丰富的参考资料和指导，有助于提高他们的设计水平和实践能力。

开关电源文献综述第一篇：开关电源文献综述开关电源---文献综述引言在计算机，电子仪表和通讯系统中应用极为广泛的开关电源，在近半个世纪的发展过程中，因具有轻小，高效等优点而逐渐取代传统技术制造的连续工作电源，成为电子电源中的主流产品。

人们在开关电源的技术领域里，一边开发相关电子技术，一边开发新型功率材料和元器件，两者相互促进推动着开关电源向轻小薄低噪声高可靠抗干扰方向发展，每年超过两位数的增长率。

开关电源分为AC/DC和DC/AC两大类。

主要应用于计算机，通讯办公室，控制设备，电子仪器等投资类产品及电视机，摄像机，VCD，电子游戏机等消费类产品。

目前全球开关电源制造商约500家。

据国外专家预计，世界开关电源的销量额将由1992年的84亿美元猛增至1999年得166亿美元，刺激开关电源市场进一步扩大并将继续推动开关电源技术进步的主要用户是计算机及外围设备，另外，快速发展的通讯及消费市场也正逐渐引起开关电源制造商的关注。

因此，研究开关电源是非常有必要的，对于我们以后的发展是很有帮助的。

因此，本文将围绕开关电源的高效性，可靠性，模块化，稳定性，低噪声，抗电磁干扰及应用等方面展开详细论述，论述是将借鉴近年来大量的文献，以此增加说服力。

正文开关电源的功率和效率问题为了使开关电源轻，小，薄，高频化（开关电源频率达兆赫级）是必然发展趋势。

而高频化有必然使传统的PWM开关功耗加大，效率降低，噪声也提高了，达不到高频，高效的预期效益，因此实现零电压导通，零电流关断软开关技术成为开关电源的主流。

采用软开关技术可使效率达到85%~88%。

开关电源是电源的发展方向，但是开关电源功率因数很低，它的输入电流波形严重畸变，所含谐波对电网有干扰，股提高功率因数，抑制谐波，减小对电网的干扰是重要的课题。

通常抑制谐波，改善功率因数的三种常用方法是串联谐振滤波器，并联谐振滤波器，升压式变换器。

其中有源式升压式变换器是提高功率因数的最好的方法。

摘要：本文介绍一种以KA3525作为控制核心，根据KA3525的应用特点，设计了一种基于该电流型PWM控制芯片、实现输出电压可调的开关稳压电源电路。

开关电源是利用现代电子技术，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）和MOSFET构成。

开关电源和线性电源相比，二者的成本都随着输出功率的增加而增长，但二者增长速率各异。

开关电源比普通的线性电源效率高，开关电源的发展与应用在节约能源、节约资源及保护环境方面都具有重要的意义。

关键词：KA3525、开关电源、PWM目录绪论---------------------------------------------------------------------------------------------第一章开关电源介绍--------------------------------------------------------1．1 开关电源发展---------------------------------------------1．1．1 国际发展状况----------------------------------------------1．1．2 国内发展情况----------------------------------------------1．1．3 开关电源优点-----------------------------------------------第二章开关电源种类------------------------------------------------------------2. 1 按激励方式划分-------------------------------------------------------2. 2 按调制方式划分-----------------------------------------------2．3 按功率开关的类型划分----------------------------------2．4 按功率开关的连接方式划分--------------------------------2．5 按输入和输出电压的大小划分-----------------------------2．6 按工作方式划分-------------------------------------------------第三章系统设计------------------------------------------------------------------------3.1 主电路的整体简介----------------------------------------3.1.1 它激型推挽式电路工作原理---------------------------------3.1.2 驱动电路---------------------------------------------------3.1.3 KA3525工作原理---------------------------------------------3.1.4 死区时间设置--------------------------------------------------3.1.5 检测电路--------------------------------------------------------3.2 参数设计-------------------------------------3.2.1 输入滤波电容--------------------------------3.2.2 原副边变比-----------------------------------3.2.3 输出滤波电容的选择---------------------------第四章实际工作中遇到的问题及解决方法------------------------------------------------------ 总结------------------------------------------ ----------------------------------------------------参考文献绪论电子技术的高速发展，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、电力检测设备电源、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。

开关电源中英文对照外文翻译文献Modeling, Simulation, and Reduction of Conducted Electromagnetic Interference Due to a PWM Buck Type Switching Power Supply IA. FarhadiAbstract:Undesired generation of radiated or conducted energy in electrical systems is called Electromagnetic Interference (EMI). High speed switching frequency in power electronics converters especially in switching power supplies improves efficiency but leads to EMI. Different kind of conducted interference, EMI regulations and conducted EMI measurement are introduced in this paper. Compliancy with national or international regulation is called Electromagnetic Compatibility (EMC). Power electronic systems producers must regard EMC. Modeling and simulation is the first step of EMC evaluation. EMI simulation results due to a PWM Buck type switching power supply are presented in this paper. To improve EMC, some techniques are introduced and their effectiveness proved by simulation.Index Terms:Conducted, EMC, EMI, LISN, Switching SupplyI. INTRODUCTIONFAST semiconductors make it possible to have high speed and high frequency switching in power electronics []1. High speed switching causes weight and volume reduction of equipment, but some unwanted effects such as radio frequency interference appeared []2. Compliance withelectromagnetic compatibility (EMC) regulations is necessary for producers to present their products to the markets. It is important to take EMC aspects already in design phase []3. Modeling and simulation is the most effective tool to analyze EMC consideration before developing the products. A lot of the previous studies concerned the low frequency analysis of power electronics components []4[]5. Different types of power electronics converters are capable to be considered as source of EMI. They could propagate the EMI in both radiated and conducted forms. Line Impedance Stabilization Network (LISN) is required for measurement and calculation of conducted interference level []6. Interference spectrum at the output of LISN is introduced as the EMC evaluation criterion []7[]8. National or international regulations are the references for the evaluation of equipment in point of view of EMC []7[]8.II. SOURCE, PATH AND VICTIM OF EMIUndesired voltage or current is called interference and their cause is called interference source. In this paper a high-speed switching power supply is the source of interference.Interference propagated by radiation in area around of an interference source or by conduction through common cabling or wiring connections. In this study conducted emission is considered only. Equipment such as computers, receivers, amplifiers, industrial controllers, etc that are exposed to interference corruption are called victims. The common connections of elements, source lines and cabling provide paths for conducted noise or interference. Electromagnetic conducted interference has two components as differential mode and common mode []9.A. Differential mode conducted interferenceThis mode is related to the noise that is imposed between different lines of a test circuit by a noise source. Related current path is shown in Fig. 1 []9. The interference source, path impedances, differential mode current and load impedance are also shown in Fig. 1.B. Common mode conducted interferenceCommon mode noise or interference could appear and impose between the lines, cables or connections and common ground. Any leakage current between load and common ground could be modeled by interference voltage source.Fig. 2 demonstrates the common mode interference source, common mode currents Iandcm1 and the related current paths[]9. The power electronics converters perform as noise source Icm2between lines of the supply network. In this study differential mode of conducted interference is particularly important and discussion will be continued considering this mode only.III. ELECTROMAGNETIC COMPATIBILITY REGULATIONS Application of electrical equipment especially static power electronic converters in different equipment is increasing more and more. As mentioned before, power electronics converters are considered as an important source of electromagnetic interference and have corrupting effects on the electric networks []2. High level of pollution resulting from various disturbances reduces the quality of power in electric networks. On the other side some residential, commercial and especially medical consumers are so sensitive to power system disturbances including voltage and frequency variations. The best solution to reduce corruption and improve power quality is complying national or international EMC regulations. CISPR, IEC, FCC and VDE are among the most famous organizations from Europe, USA and Germany who are responsible for determining and publishing the most important EMC regulations. IEC and VDE requirement and limitations on conducted emission are shown in Fig. 3 and Fig. 4 []7[]9.For different groups of consumers different classes of regulations could be complied. Class A for common consumers and class B with more hard limitations for special consumers are separated in Fig. 3 and Fig. 4. Frequency range of limitation is different for IEC and VDE that are 150 kHz up to 30 MHz and 10 kHz up to 30 MHz respectively. Compliance of regulations is evaluated by comparison of measured or calculated conducted interference level in the mentioned frequency range with the stated requirements in regulations. In united European communitycompliance of regulation is mandatory and products must have certified label to show covering of requirements []8.IV. ELECTROMAGNETIC CONDUCTED INTERFERENCE MEASUREMENTA. Line Impedance Stabilization Network (LISN)1-Providing a low impedance path to transfer power from source to power electronics converter and load.2-Providing a low impedance path from interference source, here power electronics converter, to measurement port.Variation of LISN impedance versus frequency with the mentioned topology is presented inFig. 7. LISN has stabilized impedance in the range of conducted EMI measurement []7.Variation of level of signal at the output of LISN versus frequency is the spectrum of interference. The electromagnetic compatibility of a system can be evaluated by comparison of its interference spectrum with the standard limitations. The level of signal at the output of LISN in frequency range 10 kHz up to 30 MHz or 150 kHz up to 30 MHz is criterion of compatibility and should be under the standard limitations. In practical situations, the LISN output is connected to a spectrum analyzer and interference measurement is carried out. But for modeling and simulation purposes, the LISN output spectrum is calculated using appropriate software.For a simple fixed frequency PWM controller that is applied to a Buck DC/DC converter, it is) changes slow with respect to the switching frequency, the possible to assume the error voltage (vepulse width and hence the duty cycle can be approximated by (1). Vp is the saw tooth waveform amplitude.A. PWM waveform spectral analysisThe normalized pulse train m (t) of Fig. 8 represents PWM switch current waveform. The nth pulse of PWM waveform consists of a fixed component D/fs , in which D is the steady state duty cycle, and a variable component dn/f sthat represents the variation of duty cycle due to variation of source, reference and load.As the PWM switch current waveform contains information concerning EMI due to powersupply, it is required to do the spectrum analysis of this waveform in the frequency range of EMI studies. It is assumed that error voltage varies around V e with amplitude of V e1 as is shown in (2).fm represents the frequency of error voltage variation due to the variations of source, reference and load. The interception of the error voltage variation curve and the saw tooth waveform with switching frequency, leads to (3) for the computation of duty cycle coefficients []10.Maximum variation of pulse width around its steady state value of D is limited to D1. In each period of Tm=1/fm , there will be r=fs/fm pulses with duty cycles of dn. Equation (4) presents the Fourier series coefficients Cn of the PWM waveform m (t). Which have the frequency spectrum of Fig.9.B-Equivalent noise circuit and EMI spectral analysisTo attain the equivalent circuit of Fig.6 the voltage source Vs is replaced by short circuit and) as it has shown in Fig. 10. converter is replaced by PWM waveform switch current (IexThe transfer function is defined as the ratio of the LISN output voltage to the EMI current source as in (5).The coefficients di, ni (i = 1, 2, … , 4) correspond to th e parameters of the equivalent circuit. Rc and Lc are respectively the effective series resistance (ESR) and inductance (ESL) of the filter capacitor Cf that model the non-ideality of this element. The LISN and filter parameters are as follows: CN = 100 nF, r = 5 Ω, l = 50 uH, RN =50 Ω, LN=250 uH, Lf = 0, Cf =0, Rc= 0, Lc= 0, fs =25 kHzThe EMI spectrum is derived by multiplication of the transfer function and the source noise spectrum. Simulation results are shown in Fig. 11.VI. PARAMETERS AFFECTION ON EMIA. Duty CycleThe pulse width in PWM waveform varies around a steady state D=0.5. The output noise spectrum was simulated with values of D=0.25 and 0.75 that are shown in Fig. 12 and Fig. 13. Even harmonics are increased and odd ones are decreased that is desired in point of view of EMC.On the other hand the noise energy is distributed over a wider range of frequency and the level of EMI decreased []11.B. Amplitude of duty cycle variationThe maximum pulse width variation is determined by D1. The EMI spectrum was simulatedwith D1=0.05. Simulations are repeated with D1=0.01 and 0.25 and the results are shown in Fig.14and Fig.15.Increasing of D1 leads to frequency modulation of the EMI signal and reduction in level of conducted EMI. Zooming of Fig. 15 around 7th component of switching frequency in Fig. 16 shows the frequency modulation clearly.C. Error voltage frequencyThe main factor in the variation of duty cycle is the variation of source voltage. The fm=100 Hz ripple in source voltage is the inevitable consequence of the usage of rectifiers. The simulation is repeated in the frequency of fm=5000 Hz. It is shown in Fig. 17 that at a higher frequency for fm the noise spectrum expands in frequency domain and causes smaller level of conducted EMI. On the other hand it is desired to inject a high frequency signal to the reference voltage intentionally.D. Simultaneous effect of parametersSimulation results of simultaneous application of D=0.75, D1=0.25 and fm=5000 Hz that leadto expansion of EMI spectrum over a wider frequencies and considerable reduction in EMI level is shown in Fig. 18.VII. CONCLUSIONAppearance of Electromagnetic Interference due to the fast switching semiconductor devices performance in power electronics converters is introduced in this paper. Radiated and conducted interference are two types of Electromagnetic Interference where conducted type is studied in this paper. Compatibility regulations and conducted interference measurement were explained. LISN as an important part of measuring process besides its topology, parameters and impedance were described. EMI spectrum due to a PWM Buck type DC/DC converter was considered and simulated. It is necessary to present mechanisms to reduce the level of Electromagnetic interference. It shown that EMI due to a PWM Buck type switching power supply could be reduced by controlling parameters such as duty cycle, duty cycle variation and reference voltage frequency.VIII. REFRENCES[1] Mohan, Undeland, and Robbins, “Power Electronics Converters, Applications and Design” 3rdedition, John Wiley & Sons, 2003.[2] P. Moy, “EMC Related Issues for Power Electronics”, IEEE, Automotive Power Electronics, 1989, 28-29 Aug. 1989 pp. 46 – 53.[3] M. J. Nave, “Prediction of Conducted Interference in Switched Mode Power Supplies”, Session 3B, IEEE International Symp. on EMC, 1986.[4] Henderson, R. D. and Rose, P. J., “Harmonics and their Effects on Power Quality and Transformers”, IEEE Tra ns. On Ind. App., 1994, pp. 528-532.[5] I. Kasikci, “A New Method for Power Factor Correction and Harmonic Elimination in Power System”, Proceedings of IEEE Ninth International Conference on Harmonics and Quality of Power, Volume 3, pp. 810 – 815, Oct. 2000.[6] M. J. Nave, “Line Impedance Stabilization Networks: Theory and Applications”, RFI/EMI Corner, April 1985, pp. 54-56.[7] T. Williams, “EMC for Product Designers” 3rd edition 2001 Newnes.[8] B. Keisier, “Principles of Electromagnetic Compatibility”, 3rd edition ARTECH HOUSE 1987.[9] J. C. Fluke, “Controlling Conducted Emission by Design”, Vanhostrand Reinhold 1991.[10] M. Daniel,”DC/DC Switching Regulator Analysis”, McGrawhill 1988[11] M. J. Nave,” The Effect of Duty Cycle on SMPS Common Mode Emission: theory and experiment”, IEEE National Symposium on Electromagnetic Compatibility, Page(s): 211-216, 23-25 May 1989.基于压降型PWM开关电源的建模、仿真和减少传导性电磁干扰IIA. Farhadi摘要：电子设备之中杂乱的辐射或者能量叫做电磁干扰(EMI)。

开关电源外文文献DC Switching Power Supply Protection TechnologyAbstract : 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 design1、IntroductionDC 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 protectionDC 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. 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, whilethe polarity protection circuit as a procedure to protect a link, save the power required for polarity protection diodes, power consumption will be reduced. Inorder to easy to operate, make it easier to identify the correct polarity or not, collect the next light.3、procedures to protectSwitching 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 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. Sucha 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, andthe transient process in the boot after a short period then automatically relays itto 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 bein 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, -circuit→shortcurrent 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 switchingtransistor 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 ofa boot to tie in with the soft start.4、over-current protectionWhen the load short-circuit, overload control circuit failure or unforeseen circumstances, such as would cause the flow of switching voltage regulator transistor current is too large, so that increased power tubes, fever, if there is no over-current protection device, high power switching transistor may be damaged. Therefore, the switching regulator in the over-current protection is commonly used. The most economical way is to use simple fuse. As a result of the heat capacity of small transistors, general fuse protection in general can not play a role in the rapid fuse common fuse. This method has the advantage of the protection of vulnerable, but it needs to switch transistor in accordance with specific security requirements of the work area to select the fuse specifications. This disadvantage is over-current protection measures brought about by the inconvenience of frequent replacement of fuses.Linear voltage regulator commonly used in the protection and current limitingto protect the cut-off in the switching regulator can be applied. However, according to the characteristics of switching regulators, the protection circuit can not directly control the output transistor switches, and overcurrent protection must be converted to pulse output commands to control the modulator to protect the transistor switch. In order to achieve over-current protection are generally required sampling resistor in series in the circuit, thiswill affect the efficiency of power supply, so more for low-power switching regulator of occasions. In the high-power switching power supply, by taking into account the power consumption should be avoided as far as possible access to the sampling resistor. Therefore, there will usually be converted to over-current protection, and under-voltage protection.5、over-voltage protectionSwitching regulator's input over-voltage protection, including over-voltageprotection and output over-voltage protection. Switching regulator is not used inDC power supply voltage regulator and rectifier, such as battery voltage, if toohigh, so switching regulator is not working properly, or even damage to internaldevices, therefore, it is necessary to use the input over-voltage protection circuit.In the circuit, when the input DC power supply voltage higher than thevoltage regulator diode breakdown voltage value, the breakdown voltageregulator tube, a current flowing through resistor R, so that V turn-on transistor,relay, normally closed contact off open, cut off the input. Voltage regulatorvoltage regulator which controls the value of Vz = ESrmax-UBE. The polarity ofinput power with the input protection circuit can be combined with over-voltageprotection, polarity protection constitute a differential circuit and overvoltage protection.Output over-voltage protection switching power supply is essential. Inparticular, for the 5V output of the switching regulator, it is a lot of load on ahigh level of integration of the logic device. If at work, switching regulatorsudden damage to the switch transistor, the output potential may be increasedimmediately to the importation of non-regulated DC power supply voltage value,causing great loss instantaneous. Commonly used method is short-circuitprotection thyristor. The simplest over-voltage protection circuit. When theoutput voltage is too high, the regulator tube breakdown triggered thyristorturn-on, the output short-circuit, resulting in over-current through the fuse orcircuit protective device to cut off the input to protect the load. This circuit is equivalent to the response time of the o pening time of thyristor is about 5 ~ 10 μ s. The disadvantage is that its action is fixed voltage, temperature coefficient, andaction points of instability. In addition, there is a voltage regulator control parameters of the discrete, model over-voltage start-up the same but hasdifferent values, difficult to debug.6、under-voltage protectionOutput voltage below the value to reflect the input DC power supply, switching regulator output load internal or unusual occurrence. Input DC power supplyvoltage drops below the specified value would result in switching regulator outputvoltage drops, the input current increases, not only endanger the switchingtransistor, but also endanger the input power. Therefore, in order to set up due tovoltage protection.When no voltage regulator input normal, ZD breakdown voltage regulator tube, transistors V conduction, the relay action, contact pull-in, power-switching regulator.When the input below the minimum allowable voltage value, the regulator tube ZDbarrier, V cut-off, contact Kai-hop, switching regulator can not work. Internalswitching regulator, as the control switch transistor circuit disorders or failure willdecrease the output voltage; load short-circuit output voltage will also decline.Especially in the reversed-phase step-up or step-up switching regulator DC voltageof the protection due to over-current protection with closely related and thereforemore important. Implementation of Switching Regulators in the termination of theoutput voltage comparators.Normally, there is no comparator output, once the voltage drops below the allowable value in the comparator on the flip, drive alarm circuit; also fedback to the switching regulator control circuit, so that switching transistor cut-off or cut off the input power.7、over-temperature protectionSwitching regulator and the high level of integration of light-weight small volume, with its unit volume greatly increased the power density, power supplycomponents to its work within the requirements of the ambient temperature isalso a corresponding increase. Otherwise, the circuit performance willdeteriorate, premature component failure. Therefore, in high-power switchingregulator should be set up over-temperature protection.Relays used to detect the temperature inside the power supply temperature, when the internally generated power supply overheating, the temperature of therelay on the action, so that whole circuit in a warning alarm, and the realizationof the power supply over-temperature protection. Temperature relay can beplaced in the vicinity of the switching transistor, the general high-power tube shell to allow the maximum temperature is 75 ℃ , adjust the temperature settingto 60 ℃ . When the shell after the temperature exceeds the allowable value to cut off electrical relay on the switch protection. Semiconductor switching device thermal "hot thyristor," in the over-temperature protection, played an important role. It canbe used as directed circuit temperature. Under the controlof p-hot-gate thyristor (TT102) characteristics, by RT value to determine the temperature of the device turn-on, RT greater the temperature the lower the turn-on.When placed near the power switching transistor or power device, it will be able to play the role of temperature instructions. When the power control the temperature of the shell or the internal device temperature exceeds the allowed value, the heat conduction thyristor on, so that LED warning light. If the optocoupler with, would enable the whole circuit alarm action to protect the switching regulator. It can also be used as a power transistor as the over-temperature protection, crystal switch the base current by n-type gate control thyristor TT201 thermal bypass, cut-off switch to cut off the collector current to prevent overheating.8、ConclusionDiscussed above in the switching regulator of a variety of conservation, and introduces a number of specific ways to achieve. Of a given switching power supply is concerned, but also protection from the whole to consider the following points:1)the switching regulator used in the switching transistor in the DC security restrictions on the work of regional work. The transistor switches selected by the manual available transistors get DC safe working area. According to the maximum collector current to determine the input value of over-current protection. However, the instantaneous maximum value should be converted to the average current. At rated output current and output voltage conditions, the switch of the dynamic load line does not exceed a safe working area DC maximum input voltage, input over-voltage protection is the voltage value.2)the switching regulator output limit given by the technical indicators within. Work within the required temperature range, the switching regulator'soutput voltage, the lower limit of the output is off, due to the voltage value of voltage protection. Over-current protection can be based on the maximum output current to determine. False alarm in order not to protect the value of a certain margin to remain appropriate.3)from the above two methods to determine the protection after the power supply device in accordance with the needs of measures to determine the alarm. Measures the general alarm sound and light alarm two police. Voice of the police applied to more complex machines, power supply parts and do not stand out in a place, it can give staff an effective warning of failure; optical Police instructions can be eye-catching and fault alarm and pointed out that the fault location and type. Protection measures should be protected as to determine the location. In the high-power, multi-channel power supply, always paying, DC circuit breakers, relays, etc. high-sensitivity auto-protection measures, to cut off the input power supply to stop working the system from damage. Through the logic control circuit to make the appropriate program cut-off switch transistor is sensitive it is convenient and economic. This eliminated large, long response time, the price of your high-power relay or circuit breaker.4)the power of putting in the protection circuit will be affected after the reliability of the system, for which want to protect the reliability of the circuit itself is higher in order to improve the reliability of the entire power system, thereby increasing its own power supply MTBF. This requires the protection ofstrict logic, the circuit is simple, at least components, In addition to the protection circuit should also be considered a failure of maintenance of their difficulty and their power to protect the damage.Therefore, we must be comprehensive and systematic consideration of a variety of switching power supply protection measures to ensure the normal operation of switching power supplies and high-efficiency and high reliability.。

开关电源文献综述文献综述引言21世纪我国通信、信息、家电和国防等领域的电源普遍采用高频开关电源，相控电源将逐渐被淘汰。

经过20多年的不断发展，开关电源技术有了重大的突破和进步。

新型功率器件的开发促进了开关电源的高频化，功率MUSFET 和IGBT 可使中小型开关电源工作频率达到400KH Z，软开关技术使高频开关电源的实现有了可能，它不仅可以减少电源的体积和重量，而且提高了电源的效率；控制技术的发展以及专用控制芯片的生产，不仅使电源电路大幅度简化，而且使开关电源的动态性能和可靠性大大提高[1]。

开关电源的高频化是电源技术发展的创新技术，高频化带来的效益是使开关电源装置空前的小型化，并使开关电源进入更广泛的领域，特别是在高新领域的应用，推动到了高新技术产品的小型化、轻便化，另外开关电源的发展与应用在节约资源与保护环境方面都具有深远的意义[3]。

21世纪开关电源的发展技术追求和发展趋势可以概括为以下四个方面：①小型化、轻量化、高频化；②高可靠性；③低噪声；④采用计算机辅助设计和控制[4]。

主体开关电源的基本构成如图1[6]所示，其中DC/DC 变换器用于进行功率转换，是开关电源的核心部分，此外还有软启动、过流与过压保护等电路。

输出采样电路检测输出电压变化，并与基准电压进行比较，误差电压经过放大及脉宽调制（PWM ）电路，再经过驱动电路控制功率器件的占空比，从而达到调整输出电压大小的目的。

DC/DC 变换器有多种电路形式，常见的有工作波形为方波的PWM 变换器以及工作波形为准正弦波的谐振型变换器，在本设计中采用PWM 变换器来控制功率器件的占空比。

本设计主要由四个部分组成：1）整流滤波电路；2）升压斩波电路；3）PWM 脉宽调制电路；4）按键显示电路。

1. 单相桥式整流滤波电路单相桥式整流滤波电路如图2[1]所示。

负载R L 未接入（开关S 断开）时的情况：设电容器两端初始电压为零，接入交流电源后，当v 2为正半周时，v 2通过D 1、D 3向电容器C 充电； v 2为负半周时，经D 2、D 4向电容器C 充电，充电时间常数为。

摘要开关电源因其具有稳压输入范围宽、效率高、功耗低、体积小、重量轻等显著特点而得到了越来越广泛的应用，从家用电器设备到通信设施、数据处理设备、交通设施、仪器仪表以及工业设备等都有较多应用，尤其是作为便携式产品的电池提供高性能电源输出，比其他结构具有不可超越的优势。

开关电源的稳定性直接影响着电子产品的工作性能,误差放大器是直流开关电源系统中电压控制环路的核心部分，其性能优劣直接影响着整个直流开关电源系统的稳定性，因而对高性能误差放大器的分析是本论文的主要研究目标。

本文误差放大器的分析基于Buck型DC-DC转换器，从系统稳定性、负载调整率及响应速度要求的角度出发，首先对该款Buck型DC-DC转换器的系统电压控制环路进行小信号分析,并对控制环路进行了零极点分布分析，确定环路补偿策略。

最后基于系统级来分析误差放大器。

关键词：开关电源；Buck型DC-DC转换器；误差放大器。

AbstractDue to their merits of wide input range, high efficiency, small in size and light in weight ect, switching power supplies are gaining more and more application areas in today’s modern world, ranging from domestic equipments to sophisticated communication and data handling systems, especially in portable devices, they have unsurpassable advantages.The rapid development of products in corresponding application areas requires the power supplies to have better performances. The robustness of switch—mode power supplies directly affect the performance of electronic devices. As one of the most important parts of switched mode DC to DC converters, error amplifier has significant influences on the voltage control loop’s stability. Thus this paper focuses on the design of high performance error amplifier for DC-DC converters based on system requirements analysis. A buck DC-DC converter was concerned, an error amplifier for the buck converter was designed from the points of view of system stability, load regulation and response speed requirements. At the first place, the Buck DC-DC converter’s voltage control loop stability and pole-zero analysis was done based on a small signal model of the voltage control loop, the compensation scheme was proposed. At last, according to the system level to analysis the error amplifier.Key words：Switching power; Buck DC-DC Converter; Error Amplifier.目录摘要 (I)Abstract (II)1. 诸论 (1)1.1 引言 (1)1.2 本文研究的目的与意义 (1)1.3 本论文主要研究内容 (1)2. 开关电源基础及其类型 (2)2.1 开关电源基础理论 (2)2.1.1开关电源基本工作原理 (2)2.1.2开关电源的组成 (2)2.1.3开关电源的各种分类 (3)2.2 开关电源典型结构[6] (4)2.3 DC-DC变换器 (7)2.3.1Buck变换器 (8)3.3.2Boost变换器 (10)3. Buck型DC-DC转换器及其控制方式分析 (12)3.1 Buck型DC-DC转换器 (12)3.2 Buck型DC-DC转换器及其控制方式 (13)3.2.1Buck型DC-DC转换器工作原理 (13)3.2.2Buck型DC-DC转换器的控制方式 (14)3.2.3Buck型DC-DC转换器工作模式 (18)3.3 环路控制中误差放大器的重要作用 (18)4. 开关电源管理电路系统分析 (19)4.1 Buck型DC-DC转换器 (19)4.2 开关电源控制环路的分析研究 (20)4.2.1Buck型DC-DC转换器稳定性分析 (20)4.2.2Buck型转换器电压环路控制模型 (21)5. 误差放大频率特性及其补偿策略 (27)5.1 控制电路的频率响应分析 (27)5.1.1频率响应 (27)5.1.2开关电源输出滤波电路分析 (28)5.2 开关电源中负反馈及自激振荡分析 (30)5.2.1负反馈自激振荡 (30)5.2.2误差放大电路稳定分析 (30)5.3 补偿误差放大器及频率校正策略 (32)5.3.1I类补偿误差放大器 (32)5.3.2Ⅱ类补偿误差放大器 (32)5.3.3Ⅲ型补偿误差放大器 (34)6. 闭环设计中误差放大器的分析与研究 (36)6.1 闭环控制系统中的误差放大分析 (36)6.2 环路增益 (38)6.2.1带有LC滤波电路的环路增益 (38)6.2.2PWM增益 (39)6.2.3取样增益－反馈系数 (40)6.2.4输出LC滤波器的总增益 (40)6.3 误差放大器的特性分析 (40)6.3.1误差放大器的幅频特性整形 (40)6.3.2误差放大器的传递函数、极点和零点 (42)6.3.3零点、极点和频率增益斜率变化 (43)6.4 误差放大器零点、极点的分析与计算 (43)6.4.1Ⅱ型误差放大器零点和极点分析 (43)6.4.2采用Ⅲ型误差放大器及其传递函数 (45)6.4.3Ⅲ型误差放大器的相位滞后分析 (45)6.4.4Ⅲ型误差放大器零点和极点计算 (46)6.5 反馈环路条件稳定探讨 (47)结论 (49)致谢 (50)参考文献 (51)1. 诸论1.1 引言随着电力电子及电子技术的迅猛发展，开关电源在计算机、通信、工业自动化、电子和电工仪器等领域的应用更加广泛。

基于风电变桨系统的反激开关电源设计发布时间：2021-08-09T10:17:01.957Z 来源：《中国电业》2021年第11期作者：韩琨[导读] 开关电源是风电变桨系统中不可或缺的部分。

韩琨埃斯倍风电科技（青岛）有限公司山东青岛 266000摘要：开关电源是风电变桨系统中不可或缺的部分。

在风发电变桨系统中，电网质量较差，电压幅度不稳定，变化比较大，所以变桨统中使用的电源应具备大范围电压变化情况下的稳定工作能力，即应该有一个相当宽的工作电压范围。

所以设计了使用风电变桨系统的反激式开关电源。

关键词：反激开关电源；变桨系统；风电1.绪论全世界对能源、坏保问题逐渐重视，人们对绿色能源的期望越来越高，从而促进了可再生能源，尤其是风能开发利用中。

在风发电变桨系统中，电网质量较差，电压幅度不稳定变化比较大，所以变桨统中使用的电源应具备大范围电压变化情况下的稳定工作能力，有一个相当宽的工作电压范围，这样在电网电压波动很大的情况下仍能保证变桨系统的正常工作[1]。

2.变桨反激电源的拓扑结构风电变桨的电网电压波动比较大，本设计是风电变桨系统用电源，要求能在较大范围内工作。

为了降低电路中开关管承受的最大电压，必须采用双管反激变换电路。

由于双管反激变换电路，在开关管关断时，变压器漏感电流流过续流二极管反馈给电源而钳位，所以开关管的电压应力和输人电压相等，开关管只需要阻断电源电压，不像单管变换器那样阻断2倍或更高倍数的电源电压。

可见在高压输入场合双管反激电路有其特有的优点。

其主开关管的电压应力仅为输入电压，并且漏感能量能回馈到输入侧，也不需要增加任何吸收电路，因而整机效率也比较高。

该变换器非常适用于较高输入电压、较高性能要求的场合[2]。

双管反激变换电路的拓扑结构如图1所示。

图中Q1和Q2为主开关管，高频变压器TI原边绕组通过两只主开关管接向直流电源Vin，两个主开关管需要同时导通，同时截止，因此这就要求通过两个是相同相位的但是又互相隔离的信号来驱动，一般使用一个小型的双绕组输出的变压器T2。