春西交《电力拖动自动控制系统》在线作业 满分答案

1、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, forwa

2、rd 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 spee

3、d feedback voltage can not change the speedB. if the given voltage is constant, the partial pressure ratio that 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 chan

4、ge 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 e

5、lectric 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 mo

6、tor 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 t

7、o 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

8、 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

9、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 th

10、e 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 pol

11、arity 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 1500150r/min, static slip 2% system, static downhill open loop system is 100r/min, the closed loop systems open-loop amplification (wh

12、at).A. 30B. 31.7C. 33.2D. 28Full marks: 28. a range of speed closed-loop speed control system is 1500150r/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

13、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 synchrono

14、us, 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 b

15、ehind, 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

16、 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

17、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 ca

18、scade, 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 sho

19、uld 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

20、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 th

21、e 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

22、 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 const

23、ant 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 a

24、chieve 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

25、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 lo

26、ad 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

27、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 co

28、pper 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,

29、 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 reg

30、ulation 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 with

31、out 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 si

32、mple, 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 armat

33、ure 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 syn

34、chronous motor is greater than that of asynchronous motor.A. is narrowerB. widerSame as C.Full marks: 2Online operation of electric drive automatic control systemTotal score: 100 test time: -Radio examinationA multiple-choice questionJudgment question, (a total of 10 multiple-choice questions, a tot

35、al 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, h

36、igh 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

37、 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

38、 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 regul

39、ation 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 i

40、s ().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 he

41、ating 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 d

42、erivative (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 the steady-state (downhill).Mec

43、hanical 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 base

44、d 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 systemTotal score: 100 test time: -Radio examinationA multiple-choice questionJudgment questionJudgment questions (a total

45、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