Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Chapter 57, Problem 2SQ
To determine
Explain the procedure to obtain the above base speed of a DC motor.
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Give the definition of percentage speed regulation.
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(1) A dc drives are operating in- - quadrants when the supply voltage is- --than the back emf,
and in the --------quadrants when the supply voltage is ---------------than the back emf.
„For a speed less than the base speed, the -----
-are maintained constant at their rated value (2)
.and the---------is varied to control the speed
(3) In a single phase semi-converter dc drives a freewheeling diode is used to ensure-
(4) In a single phase full-converter dc drives, the motor is operating in the 1ª quadrants if the armature
converter firing angle is-----and in the 4 th quadrants if the armature converter firing angle is-------.
(5) In constant power drive, the speed is controlled by
(ii) What is displacement power factor and true power factor?
Describe the significance of these power factors for a
non-liner load like PWM based variable frequency
drives.
Chapter 57 Solutions
Electric Motor Control
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- (ii) Briefly describe the working principle of induction motor speed control for below and above base speed using constant Volts/Hertz (V/f) technique. Torque-speed curve diagram can be used to support the description.arrow_forward6. The block diagram of a video tape drive is shown in Figure Q.6. It is important for the quality of the video image that the tape spool is rotated at a particular reference speed, 0,. The actual speed of the tape, w, is sensed, and fed back, any error, E(s) being passed to the controller, G(s), which controls the torque motor. The tape is also subject to torque disturbance, D(s) due to frictional and other effects. a) It is proposed to use a simple proportional controller. Assuming there is no disturbance, calculate the necessary proportional gain, K,, if the maximum allowable steady state error is 2% in response to a unit step change in reference speed, w,. b) Derivative action is added to the controller. Calculate the necessary proportional and derivative gains K, and K, if the rise time is to be 0.04s and the peak time is to be 0.1s in response to a unit step change in reference speed, assuming no disturbance. c) Using the controller designed in part b), calculate the steady state…arrow_forward6. The block diagram of a video tape drive is shown in Figure Q.6. It is important for the quality of the video image that the tape spool is rotated at a particular reference speed, m,. The actual speed of the tape, o, is sensed, and fed back, any error, E(s) being passed to the controller, G(s), which controls the torque motor. The tape is also subject to torque disturbance, D(s) due to frictional and other effects. a) It is proposed to use a simple proportional controller. Assuming no change in reference speed, calculate the necessary proportional gain, K„, if the maximum allowable steady state error is 0.01rad/s in response to a step disturbance torque of 1Nm. b) Derivative action is added to the controller. Calculate the necessary proportional and derivative gains K, and K,, if the maximum allowable overshoot in speed is 20%, and the speed must settle to its final value in less than 0.25s in response to a unit step change in reference speed, assuming no disturbance. c) Using the…arrow_forward
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