Deck 24: Electronic Variable Speed Drives

Question 1

The voltage that is set for the desired speed of the motor is called the ____.

A) feedback signal
C) reference signal
B) error signal
D) sawtooth signal

Answer 1

C

Question 2

The best definition of torque is ____.

A) an opposing voltage produced in the motor's armature
B) the difference between the actual speed and the desired speed of a motor
C) an undesirable phenomenon, and steps should be taken to eliminate it
D) the turning force produced by a motor

Answer 2

D

Question 3

All types of VVIs provide ____________________ protection.

Answer 3

open-circuit

Question 4

The signal that represents the difference between the control signal and the feedback signal is called the ____.

A) feedback signal
C) reference signal
B) error signal
D) sawtooth signal

Question 5

The function of the converter is to ____.

A) convert AC to DC
C) filter the DC
B) convert DC to AC
D) filter the AC

Question 6

A chopper circuit is used to ____.

A) change AC to DC
C) change pulsating DC into steady DC
B) change DC to AC
D) change steady DC into pulsating DC

Question 7

The AC sine wave supplied to the motor is artificially produced by an inverter stage in the flux vector drive.

Question 8

Which inverter cannot operate from battery power?

A) Chopper-controlled VVI
C) Chopper-controlled CSI
B) Phase-controlled CSI
D) PWM

Question 9

PWM stands for ____.

A) permanent magnet motor
C) partial winding motor
B) perfectly whirling machine
D) pulse-width modulation

Question 10

____________________ drives operate by monitoring rotor position and changing the rotor's position as compared to its orientation to the stator field.

Question 11

When using a DC motor with a DC drive, the most common DC motor connection is the ____.

A) series wound DC motor
B) self-excited shunt wound DC motor
C) separately excited DC motor
D) compound wound DC motor

Question 12

The inverter stage in a flux vector drive allows ____.

A) control over the synthetic AC
C) current to be stepped down
B) AC to be turned into DC current
D) voltage to be removed

Question 13

The DC link is also called ____.

A) the DC bus
C) the inverter
B) the converter
D) pulsating DC

Question 14

A step change is a(n) ____________________ in the motor rotation due to an advancement in the flux field.

Question 15

In a Current Source Inverter, ____________________ is controlled while the voltage is varied to satisfy the motor's needs.