吉大15春学期《电力拖动自动控制系统》在线作业二

15春西交《电力拖动自动控制系统》在线作业满分答案Austrian Peng 15 spring West to "electric drive automatic control system" online homeworkTotal score: 100 test time: -Radio examinationA multiple-choice questionJudgment questionRadio examination questions (30 questions, 60 points)1. V-M system in four quadrant operation, forward braking ().A. the polarity of the armature terminal is negativeB. armature current polarity is positiveC. mechanical characteristics are in the second quadrantFull marks: 22. the following statement is correct.A. if the given voltage is constant, the partial pressure ratio that regulates the speed feedback voltage can not change the speedB. if the given voltage is constant, the partial pressure ratiothat regulates the speed feedback voltage does not necessarily change the speedC. if the given voltage is constant, the partial pressure ratio that regulates the speed feedback voltage can change the speedFull marks: 23. speed range means ().A. production machinery requires that the ratio of the maximum speed to the minimum speed provided by an electric motor is called the speed rangeB. production machinery requires that the ratio of the minimum speed to the maximum speed provided by an electric motor is called the speed rangeC. production machinery requires that the ratio of the average speed to the minimum speed provided by an electric motor is called the speed rangeD. production machinery requires that the ratio of the maximum speed to the average speed provided by an electric motor is called the speed rangeFull marks: 24. what are the basic characteristics of speed single closed loop speed regulation system?.A. uses only the proportional amplifier feedback control system, its modulation quantity still has no static difference.The function of B. feedback control system is to resist disturbance and obey the given. Disturbance performance is one of the most prominent characteristics of feedback control systemThe accuracy of the C. system depends only on the given accuracyThe accuracy of D. system depends only on the accuracy of feedback detectionFull marks: 25. when the constant voltage constant frequency sine wave power supply, the mechanical characteristic of the asynchronous motor is correct.A. when the S is very small, the torque is approximately proportional to the s, and the mechanical characteristics are a hyperbola that is symmetrical at the originB. when the S is very small, the torque is approximately inversely proportional to s, and the mechanical characteristic is a straight lineC. when the S is close to 1, the torque is approximately inversely proportional to s. At this point, Te = f (s) is a hyperbola that is symmetrical at the originD. when the S is close to 1, the torque is approximately proportional to s. At this point, Te = f (s) is a hyperbola that is symmetrical at the originFull marks: 2In the four quadrant operation of the 6. V-M system, the forward run time ().A. the polarity of the armature terminal voltage is positiveB. the polarity of the armature current is negativeC. mechanical characteristics are in the second quadrantFull marks: 27. a range of speed closed-loop speed control system is 1500~150r/min, static slip <2% system, static downhill open loop system is 100r/min, the closed loop system's open-loop amplification (what).A. 30B. 31.7C. 33.2D. 28Full marks: 28. a range of speed closed-loop speed control system is 1500~150r/min, requirement of static rate of <2% system, then the system is allowed (static downhill).A. 3.06r/minB. 2.8r/minC. 3.46r/minD. 4.00r/minFull marks: 29., the static frequency conversion device can be divided into (two) types.A.Indirect frequency conversion and direct frequency conversionB. only direct frequency conversionC. only indirect frequency conversionD. or more is incorrectFull marks: 2The advantage of 10. synchronous motors is thatA. speed and voltage, frequency strictly synchronous, power factor is as high as 1B. difficult to startThere are oscillations in C. overloading and even risk of missing stepFull marks: 211. power factor of synchronous motor ()A. can be adjusted by excitation current, which can be delayed or advancedB. can not be delayed or advancedC. can only lag behind, can not advanceFull marks: 212. when the speed and current double closed loop speed regulation system runs in a steady state, the input bias voltage and output voltage of the two regulators are wrong.A. when the two regulators are not saturated, their input bias voltage is zeroB. when the two regulators are not saturated, their input bias voltage is not zeroThe output limiting voltage of the C. speed regulator ASR determines the maximum value of the current given voltageThe output limiting voltage of the D. current regulator ACR limits the maximum output voltage of the power electronic converterFull marks: 2In the four quadrant operation of the 13. V-M system, the reverse run time ().A. the polarity of the armature terminal voltage is positiveB. armature current polarity is positiveC. mechanical characteristics are in the third quadrantFull marks: 214. direct start, also called cascade, allows the inverter to start in a fast manner. The rotor is connected with the AC network when the starting controller turns on the AC network, and then the rotor is ()A. high impedance stateB. closed stateC. open stateFull marks: 215. for the cascade speed regulation system, the starting should be large enough rotor current Ir or large enough rectifier DC current Id, therefore, the rotor rectifier voltage Ud and the inverter voltage Ui should ()A. larger differenceB. smaller differenceC. the same differenceFull marks: 216. the definition of static rate is ().A. when the system runs at a certain speed, the load falls from ideal no-load to rated value, and the speed drops at the ratio of ideal no-load speedB. when the system runs at a certain speed, the load falls from ideal no-load to the rated value, and the speed drops as compared with the rated valueFull marks: 217. which of the following is not a step-down starter?.A. star delta (Y- delta) startB. stator series resistance or reactance startingC. autotransformer step-up startFull marks: 218. when the parameters of the asynchronous motor are constant, the electromagnetic torque Te of the motor is equal to the square of the stator voltage U at a certain speed.A. is proportional toB. is inversely proportional toC. independentFull marks: 219. the maximum speed characteristic of a speed regulation system is 1500r/min, the minimum speed characteristic is 150r/min, the speed falls 15r/min with the rated load, and the constant speed drop at different speeds remains unchangedA. system can achieve speed range of 11, the system allows the static rate of 10%B. system can achieve speed range of 10, the system allows the static rate of 10%C. system can achieve speed range of 11,The allowable static slip is 8%D. system can achieve speed range of 10, the system allows the static rate of 12%Full marks: 2Calculation of steady-state parameters of 20. double closed loop speed regulation system and steady state calculation of non static differential system.A. is exactly the sameB. similarityC. has no contactFull marks: 2The feedback of the 21. position servo system is the position loop, and the feedback of the speed governing system is ().A. speed ringB. position ringC. time loopFull marks: 222. series speed regulation system has no brake stopping function. Can only by () gradually slow down, and rely on the role of load resistance torque free parking.A. increases beta angleB. reduces beta angleC. increases copper consumptionFull marks: 223. induction motor magnetic field () power generation.A. stator onlyB. rotors aloneC. consists of stator and rotorFull marks: 224. power supply motivation, because of the needs of the excitation, it must be drawn from the power lag reactive current, no-load power factor is very low. The synchronous motor can change the input power factor by adjusting the DC exciting current of the rotor, and it can lag behind or advance. When cos phi =1.0 ().A. armature has the greatest copper lossB. armature copper loss minimumC. armature has the greatest iron consumptionFull marks: 225. when the regulator saturation, the output is constant, the change of input output is no longer affected, unless there is a reverse input signal makes the regulator out of saturation; in other words, the regulator temporarily cut off saturation between the input and output connection, the equivalent of the adjusting ring ()A. ring openingB. closed loopC. short circuitFull marks: 226. the following options are not the characteristics of the starting process of the double closed loop DC speed regulation system.A. saturation nonlinear controlB. speed overshootC. quasi time optimal controlD. saturation linear controlFull marks: 227., when the load current reaches Idm, the speed regulator is saturated, the current regulator plays a major role in regulating, the system behaves as a current without static difference, and gets () automatic protection.A. overcurrentB. overvoltageC. zero driftFull marks: 228. in the DC speed control system, time constant small armature current, current loop must have a sufficiently high sampling frequency, and the current regulation algorithm is relatively simple, with high sampling frequency is possible. Therefore, the current regulator can generally be designed using () methodsA. directB. indirectC. combines direct and indirectFull marks: 2In the four quadrant operation of the 29. V-M system, the reverse braking is applied.A. the polarity of the armature terminal voltage is positiveB. armature current polarity is positiveC. mechanical characteristics are in the second quadrantFull marks: 230. as the synchronous motor rotor has independent excitation, it can operate at very low power frequency, so under the same conditions, the speed range of synchronous motor is greater than that of asynchronous motor.A. is narrowerB. widerSame as C.Full marks: 2Online operation of "electric drive automatic control system"Total score: 100 test time: -Radio examinationA multiple-choice questionJudgment question, (a total of 10 multiple-choice questions, a total of 20 points.)1. PWM - motor system has greater advantages in () aspect.The main circuit of the A. is simple and requires less power devices.B. switching frequency is high, the current is easy to continuous, harmonic less, motor loss and heating are small.C. low speed performance, stable speed, high precision, wide speed range, up to about 1:10000.If the D. is in line with the fast response motor, the system has wide frequency band, fast dynamic response and strong dynamic immunity.Full marks: 22., from the point of view of differential power, the asynchronous motor speed control system can be divided into several categories. ()A. slip power consumption type speed regulating systemB. slip power feed speed regulation systemC. variable power differential speed regulation systemFull marks: 23. the following statement is correct.The A. static rate is used to measure the speed stability of the speed governing system under varying loadsThe harder the mechanical properties of B. are, the smaller the static rate is, and the higher the stability of the rotational speedC. speed range and static rate of two indicators, collectively referred to as the steady-state performance of speed regulation systemFull marks: 2The starting process of 4. double closed loop DC speed regulation system is characterized byA. saturation nonlinear controlB. speed overshootC. quasi time optimal controlFull marks: 25., in the design of closed-loop speed regulation system, the method of dynamic correction is ().A. series correctionB. parallel correctionC. feedback correctionFull marks: 26., the following advantages of the PWM system are ().The main circuit of A. is complex and requires more power devicesB. switching frequency is high, the current is easy to continuous, harmonic less, motor loss and heating are smallThe C. DC power supply adopts uncontrolled rectifier, and the power factor of the grid is higher than that of the phase controlled rectifierFull marks: 2The type of the 7. PID regulator includes ()A. proportional differential (PD)B. proportional integral (PI)C. proportional integral derivative (PID)Full marks: 28. what are the dynamic performance indicators of the automatic control system?A. follow performance indicatorsB. anti-jamming performance indexC. current indexD. voltage indicatorFull marks: 2The essence of 9. closed-loop system can reduce thesteady-state (downhill).Mechanical characteristics of A. closed loop speed regulation systemMechanical characteristics of B. open loop systemC. blocking currentFull marks: 2The internal logic requirement of 10. DLC is ()A. converts the input signal and converts analog to switchingThe B. makes the correct logical decision based on the input signalC. requires two delay times to ensure reliable switching between the two thyristor devicesFull marks: 2Online operation of "electric drive automatic control system" Total score: 100 test time: -Radio examinationA multiple-choice questionJudgment questionJudgment questions (a total of 10 questions, a total of 20 points)OneThe magnetic field directional flux open-loop slip vector control system is determined by the flux and torque of the given signal by the vector control equation that no actual calculated rotor flux and phase, so it belongs to the indirect vector control. ()A. errorB. correctFull marks: 22. for speed single closed loop speed regulation system, the function of feedback control system is to resist disturbance and obey the given. Disturbance performance is one of the most prominent characteristics of feedback control system. ()A. errorB. correctFull marks: 23. voltage source inverter is a constant voltage source, the voltage control response is slow and difficult to fluctuate, so it is suitable for more than one power supply of synchronous motor operation. ()A. errorB. correctFull marks: 24. the AC frequency converter composed of thyristor is mainly used for rolling mill, main drive, ball mill, cement rotary kiln and other large capacity and low speed systems. ()A. errorB. correctFull marks: 2The 5. circulation can be divided into two major categories, static circulation and dynamic circulation.A. errorB. correctFull marks: 2The DC voltage waveform of the 6. voltage source inverter is relatively flat. Under ideal conditions, a constant voltage source with a resistance of 0 is used, and the rectangular wave or trapezoidal wave is generated when the AC voltage is output. ()A. errorB. correctFull marks: 27. for the same speed control system, Delta nN value, if the more stringent of static rate requirements, which requires the s value is smaller, speed range that allows is smaller. ()A. errorB. correctFull marks: 2The 8. PWM converter has two classes: irreversible and reversible.A. errorB. correctFull marks: 29. compared with the current model, the voltage model of the rotor flux is less affected by the change of motor parameters, and the algorithm is simple and easy to use. ()A. errorB. correctFull marks: 210. dynamic landing is generally greater than steady landing. ()A. errorB. correct Full marks: 2。

------------------------------------------------------------------------------------------------------------------------------ (多选题) 1: 下列属于转速电流双闭环调速系统的起动过程的特点有（）。

A: 理想状态快速起动B: 饱和非线性控制C: 饱和线性控制D: 转速超调正确答案:(多选题) 2: 下列属于直流电动机调速方法有（）。

A: 定子串电阻B: 调节电枢两端电压C: 减弱励磁磁通D: 改变定子电压正确答案:(多选题) 3: 控制系统的动态性能指标主要有以下几类（）。

A: 超调量B: 跟随性能指标C: 抗扰性能指标D: 动态降落正确答案:(多选题) 4: 要改变电动机的旋转方向，就必须改变电动机电磁转矩的方向，改变直流电动机转矩的方法有（）。

A: 改变电动机电枢电流方向B: 改变电动机中绕组的位置C: 改变电动机电枢两端电压极性D: 改变电动机励磁磁通方向正确答案:(多选题) 5: 转速电流双闭环控制中，电流调节器的作用有？（）。

A: 对电网电压波动起及时抗扰作用B: 在转速调节过程中，使电流跟随转速调节器输出变化C: 起动时保证获得允许的最大电流D: 当电机过载时甚至于堵转时，限制电枢电流的最大值，起到限流的作用正确答案:(多选题) 6: 转速闭环系统看属于闭环可抵抗的扰动有（）。

A: 运算放大器放大倍数变化B: 反馈系数变化C: 供电电压扰动D: 电机负载变化正确答案:(多选题) 7: 对于调速系统的转速控制要求有（）。

A: 调速B: 调速范围C: 加减速D: 稳速正确答案:------------------------------------------------------------------------------------------------------------------------------ (多选题) 8: 直流电机常用的可控直流电源有（）。

吉林大学智慧树知到“电气工程及其自动化”《电力系统继电保护》网课测试题答案（图片大小可自由调整）第1卷一.综合考核(共15题)1.线路末端发生金属性三相短路时，保护安装处母线测量电压()A.为故障点至保护安装处之间的线路压降B.与短路点相同C.与线路中间段电压相同D.不能判定2.三段式电流保护中，保护范围最小的是()A.瞬时电流速断保护B.限时电流速断保护C.定时限过电流保护3.电力变压器外部相间短路应采用的保护包括()A.过电流保护B.复合电压启动的过电流保护C.负序电流及单相式低电压起动的过电流保护D.阻抗保护4.电力元件继电保护的选择性，除了决定于继电保护装置本身的性能外，还要求满足：由电源算起，愈靠近故障点的继电保护的故障起动值()A.相对愈小，动作时间愈短B.相对越大，动作时间愈短C.相对愈小，动作时间愈长D.以上都不对5.为了在正常运行和外部短路时流入变压器纵差动保护的电流为零，因此，该保护两侧应选用相同变比的电流互感器。

()A.错误B.正确6.长线路的测量阻抗受故障点过渡电阻的影响比短线路大。

()A.错误B.正确7.对称三相电路Y连接时，线电压为相电压的()倍。

A.根号3B.根号2C.2D.1.58.瓦斯保护是变压器的()A.主后备保护B.主保护C.辅助保护D.后备保护9.加装旁路母线的唯一目的是()A.不停电检修出线断路器B.吸收容性无功C.吸收感性无功D.减小停电面积10.变压器差动保护防止穿越性故障情况下误动的主要措施是()A.间断角闭锁B.二次谐波制动C.比率制动D.机械闭锁11.使阻抗继电器刚好动作的最大测量阻抗称为继电器的()。

A.整定阻抗B.测量阻抗C.动作阻抗D.固有阻抗12.差动保护只能在被保护元件的内部故障时动作，而不反应外部故障，具有绝对的()A.选择性B.速动性C.灵敏性D.稳定性13.影响输电线纵联差动保护正确工作的因素有()A.电流互感器的误差和不平衡电流B.导引线的阻抗和分布电容C.导引线的故障和感应过电压D.电压等级14.考虑助增电流的影响，在整定距离保护Ⅱ段的动作阻抗时，分支系数应取()A.大于1，并取可能的最小值B.大于1，并取可能的最大值C.小于1，并取可能的最小值D.小于1，并取可能的最大值15.双绕组变压器纵差动保护两侧电流互感器的变比，应分别按两侧()选择。

【奥鹏】-[吉林大学]吉大20春学期《电力拖动自动控制系统》在线作业一试卷总分:100 得分:100第1题,系统处于深调速状态，即较低转速运行时，晶闸管的导通角（）。

A、变大B、先变小后变大C、变小D、先变大后变小正确答案:C第2题,同步电动机（）。

A、有转差B、没有转差C、转差为1D、视具体条件而定正确答案:B第3题,( )的全部转差功率都转换成热能消耗在转子回路中。

A、转差功率消耗型调速系统B、转差功率馈送型C、转差功率不变型调速系统D、B和C正确答案:A第4题,系统的机械特性越硬，静态差越小，转速的稳定度（）。

A、越高B、越低C、先高后低D、先低后高正确答案:A第5题,在单闭环直流调速系统中，电流截止负反馈环节是专门用来控制（）的。

A、电流B、电源C、电压D、电阻正确答案:A第6题,常用的阶跃响应跟随性能指标有（）。

A、上升时间B、超调量C、调节时间D、过载时间正确答案:A,B,C第7题,双闭环直流调速系统的起动过程的特点有（）。

A、饱和非线性控制B、转速超调C、准时间控制D、动态控制正确答案:A,B,C第8题,常用的可控直流电源有（）A、旋转变流机组B、静止式可控整流器C、直流斩波器D、发射器正确答案:A,B,C第9题,双闭环直流调速系统的整个动态过程可分为（）。

A、电流上升阶段B、恒流升速阶段C、转速调节阶段D、电压调节阶段正确答案:A,B,C第10题,建立调节器工程设计方法所遵循的原则是：（）。

A、概念清楚B、计算公式简明C、指明参数调整的方向D、适用于可以简化成典型系统的反馈控制系统正确答案:A,B,C,D第11题,电流波形的断续会影响系统的运行性能。

（）A、错误B、正确正确答案:第12题,采用工程设计方法设计调节器时，应该首先根据控制系统的要求，确定要校正成哪一类典型系统。

（）A、错误B、正确正确答案:B第13题,积分调节器的输出包含了输入偏差量的全部历史。

（）A、错误B、正确正确答案:B第14题,调速系统的静态差应以最低速时所能达到的数值为标准。

2021春季西交《电力拖动自动控制系统》在线作业西交《电力拖动自动控制系统》在线作业一、单选题（共25道试题，共50分。

）1.普通逻辑并无环流（既并无发推β又并无准备工作）对称变频系统中高速运行时等待工作组资金投入工作时，电动机处在（）状态.答谢刹车.LX1刹车.能耗刹车.民主自由停放恰当答案：2.α＝β配合控制有环流可逆调速系统的主回路采用反并联接线，除平波电抗器外，还需要（）个环流电抗器.2.3.4.1恰当答案：3.采用旋转编码器的数字测速方法不包括.m法.t法.m/t法.f法恰当答案：4.下列异步电动机调速方法属于转差功率消耗型的调速系统是.降电压调速.串级调速.变极调速.变压变频调速正确答案：5.一个设计较好的双闭环变频系统在稳态工作时.两个调节器都饱和状态.两个调节器都不饱和.st饱和状态，lt不饱和.st不饱和，lt饱和状态恰当答案：6.转速pi调节器的双闭环系统与转速pi调节器的双闭环系统相比，.抗负载干扰能力弱.动态速降增大.恢复正常时间缩短.抗电网电压扰动能力增强正确答案：7.输出功率电流双闭环变频系统中输出功率调节器的英文简写就是.r.vr.sr.tr正确答案：8.输出功率―电流双闭环不可逆系统正常平衡运转后，辨认出原定正向与机械建议的也已方向恰好相反，须要发生改变电机运转方向。

此时不该.对调磁场接线.对调电枢接线.同时调换磁埸和电枢接线.同时对调磁埸和测距发电机接线恰当答案：9.系统的静态速降一定时，静差率s越小，则.调速范围越小.额定转速越大.调速范围越大.额定转速越大正确答案：10.输出为零时输入也为零的调节器就是.p调节器.i调节器.pi调节器.pi调节器恰当答案：11.当理想空载转速n0相同时，闭环系统的静差率s与开环下的ks之比为.1.0.1+k.1/（1+k）（k为开环压缩倍数）恰当答案：12.下列不属于异步电动机动态数学模型特点的是.高阶.低阶.非线性.强耦合正确答案：13.α＝β协调掌控存有环流对称变频系统的主电路中.既有直流环流又存有脉动环流.存有直流环流但并无脉动环流.既无直流环流又无脉动环流.无直流环流但有脉动环流正确答案：14.以下不属于双闭环直流变频系统启动过程特点的就是.饱和状态非线性掌控.输出功率市场汇率.准时间最优控制.饱和线性控制正确答案：15.在微机数字控制系统的中断服务子程序中中断级别最低的就是.故障维护.pwm分解成.电流调节.输出功率调节恰当答案：16.静差率和机械特性的硬度有关,当理想空载转速一定时,特性越硬,静差率.越小.越大.不变.不确定正确答案：17.输出功率电流双闭环变频系统中的两个调速器通常使用的掌控方式就是.pi.pi.p.p正确答案：18.变频系统的静差率指标应当以何时所能够达至的数值为依据.平均速度.最高速.最低速.任一速度恰当答案：19.比例微分的英文缩写是.pi.p.vr.pi恰当答案：20.在定性的分析闭环系统性能时，截止频率ω越低,则系统的稳定精度.越高.越低.不变.不确认恰当答案：21.下列交流异步电动机的调速方法中，应用最广的是.降电压调速.变极对数调速.变压变频调速.转子串电阻调速正确答案：22.控制系统能正常运转的首要条件就是.抗扰性.稳定性.快速性.准确性恰当答案：23.转速电流双闭环调速系统中电流调节器的英文缩写是.r.vr.sr.tr恰当答案：24.直流双闭环调速系统中出现电源电压波动和负载转矩波动时.r抑制电网电压波动，sr抑制转矩波动.r抑制转矩波动，sr抑制电压波动.r放大转矩波动，sr抑制电压波动.r 放大电网电压波动，sr抑制转矩波动正确答案：25.双闭环直流变频系统电流环路调试时，如果励磁电源合闸，电枢电路亦同时通电，取值由r输出端的重新加入且产生恒定的额定电流，则（）。

一、简答（每小题8分，共48分）1、无环流逻辑控制器有那几部分组成。

每部分是什么。

答：无环流逻辑控制器有四部分：电平检测、判断逻辑、延时电路、联锁保护2、双闭环直流调速系统转速和电流调节器作用。

答：双闭环直流调速系统中转速调节器的作用（1）转速调节器是调速系统的主导调节器，它使转速n很快地跟随给定电压变化，稳态时可减小转速误差，如果采用PI调节器，则可实现无静差。

（2）对负载变化起抗扰作用。

（3）其输出限幅值决定电机允许的最大电流。

电流调节器的作用（1）作为内环的调节器，在外环转速的调节过程中，它的作用是使电流紧紧跟随其给定电压（即外环调节器的输出量）变化。

（2）对电网电压的波动起及时抗扰的作用。

（3）在转速动态过程中，保证获得电机允许的最大电流，从而加快动态过程。

（4）当电机过载甚至堵转时，限制电枢电流的最大值，起快速的自动保护作用。

一旦故障消失，系统立即自动恢复正常。

这个作用对系统的可靠运行来说是十分重要的。

3、两组可逆整流装置反并联可逆线路中分析直流平均环流如何产生的。

答：直流平均环流是由于正组晶闸管和反组晶闸管均处于整流使电源短路产生的电流。

瞬时脉动环流是由于正组输出电压和反组输出电压瞬时值不同。

正组的瞬时值大于反组的瞬时值，产生电压差从而产生的电流。

4、ＳＶＰＷＭ，SPWM、电流滞环跟踪ＰＷＭ控制技术他们控制目的分别是什么。

答：SVPWM控制目的：形成圆形旋转磁场SPWM控制目的：控制输出电压为正弦波电流滞环跟踪PWM控制目的:控制电流为正弦波5、写出三相异步电动机在两相βα,坐标系下数学模型。

磁链方程电压方程转矩方程运动方程⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎣⎡=⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡rβrαsβsαrmrmmsmsrβrαsβsαiiiiLLLLLLLLψψψψ⎪⎪⎭⎪⎪⎬⎫-+=++=+=+=αββββαααβββααψψψψψψrrrrrrrrrrsssssssswpiRuwpiRupiRupiRu)(rsrsmpeβααβiiiiLnT-=tnJTTddpLeω+=6、简述直接转矩控制系统工作原理。

------------------------------------------------------------------------------------------------------------------------------ (单选题) 1: 在单闭环直流调速系统中，电流截止负反馈环节是专门用来控制（）的。

A: 电流B: 电源C: 电压D: 电阻正确答案:(单选题) 2: ( )的全部转差功率都转换成热能消耗在转子回路中。

A: 转差功率消耗型调速系统B: 转差功率馈送型C: 转差功率不变型调速系统D: B和C正确答案:(单选题) 3: 晶闸管可控整流器的放大倍数在（）以上。

A: 10B: 100C: 1000D: 10000正确答案:(单选题) 4: 为了实现转速和电流两种负反馈分别起作用，可在系统中最少设置（）个调节器。

A: 2B: 3C: 4D: 5正确答案:(单选题) 5: 从稳态上来看，电流正反馈是对（）的补偿控制。

A: 负载扰动B: 电源扰动C: 机械扰动D: B和C正确答案:(多选题) 1: 双闭环直流调速系统的整个动态过程可分为（）。

A: 电流上升阶段B: 恒流升速阶段C: 转速调节阶段D: 电压调节阶段正确答案:(多选题) 2: 常用的阶跃响应跟随性能指标有（）。

A: 上升时间B: 超调量C: 调节时间D: 过载时间正确答案:------------------------------------------------------------------------------------------------------------------------------ (多选题) 3: PID调节器中具有哪些类型？（）A: 比例微分B: 比例积分C: 比例积分微分D: 比例放大正确答案:(多选题) 4: 双极式控制的桥式可逆PWM变换器的优点是：（）。

一、简答1、和V ——M 系统相比PWM 系统有哪些优越性2、双闭环直流调速系统转速和电流调节器作用3、说明位置随动系统的组成4、从评价交流调速系统效率出发，异步电动机调速系统分为几类。

变压变频调速、转子串电阻调速、绕线转子电动机串级调速属于哪类调速5、写出异步电动机在两相任意旋转坐标系下数学模型。

6、转差频率控制的规律是什么。

二、绘制α=β配合控制有环流可逆直流调速系统正向制动过渡过程控制电压、转速、电枢电流波形。

三、已知H 型双极式可逆PWM 变换器v u s 100=，当T T on 43=时计算输出平均电压，并说明电机的转向。

四、已知控制对象的传递函数为W(s)=)1)(1)(1)(1(43211++++s T s T s T s T K 式中K1=2，T1=0.43s,T2=0.06s,T3=0.008s,T4=0.002s,要求阶跃输入下系统的超调量小于5%。

用I （积分）调节器把系统校正为典型Ⅰ型系统，设计该调节器？1、和V——M系统相比PWM系统有哪些优越性答：1）主电路线路简单，需用的功率器件少。

2）开怪频率高，电流容易连续，谐波少，电机损耗及发热都较小。

3）低速性能好，稳速精度高，调速范围宽，可达1：10000左右。

4）若与快速响应的电动机配合，则系统频带宽，动态响应快，动态抗扰能力强。

5）功率开关器件工作在开关状态，导通损耗小，当开关频率适当的时候，开关损耗也不大，因而装置效率较高。

6）直流电源采用不控整流时，电网功率因数比相控整流器高。

由于有上述优点，直流PWM 调速系统的应用日益广泛，特别是在中、小容量的高动态性能系统中，已经完全取代了V-M系统。

2、双闭环直流调速系统转速和电流调节器作用答:电流调节器的作用是：限制最大电流（过大的起动电流、过载电流），并使过载时（达到允许最大电流时）思想很陡的下垂机械特性；起动时，能保持电流在允许最大值，实现大恒流快速启动；能有效抑制电网电压波动对电流的不利影响。

吉大18春学期《电力拖动自动控制系统》在线作业二-0003
为了实现转速和电流两种负反馈分别起作用，可在系统中最少设置（）个调节器。

A:2
B:3
C:4
D:5
答案：A
稳定裕度大，动态过程振荡（）。

A:强
B:弱
C:时强时弱
D:无关
答案：B
系统的机械特性越硬，静态差越小，转速的稳定度（）。

A:越高
B:越低
C:先高后低
D:先低后高
答案：A
系统处于深调速状态，即较低转速运行时，晶闸管的导通角（）。

A:变大
B:先变小后变大
C:变小
D:先变大后变小
答案：C
同步电动机（）。

A:有转差
B:没有转差
C:转差为1
D:视具体条件而定
答案：B
双闭环直流调速系统的起动过程中转速调节器ASR经历了（）。

A:不饱和
B:饱和
C:退饱和
D:非饱和
答案：A,B,C
PID调节器中具有哪些类型？（）
A:比例微分
B:比例积分
C:比例积分微分
D:比例放大
答案：A,B,C
调速系统的稳态性能指标指（）
A:调速范围
B:静态差
C:调速时间。