1
|
Which chopper is also called as four quadrant chopper?
|
|
Type E chopper
|
2
|
What is meant by RLE load?
|
|
It is simple
motor load in which E indicates back emf of the motor.
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3
|
Which chopper is also called as two quadrant chopper?
|
|
Type B chopper
and type C chopper
|
4
|
Which type of chopper configuration is used in the Jones
chopper?
|
|
Type D chopper
|
5
|
Which circuit provides commutation for the Jones chopper?
|
|
The auxiliary
SCR, capacitor C, diode and auto transformer provide commutation circuit for
the Jones chopper.
|
6
|
Which circuit provides commutation for the Morgan chopper?
|
|
The capacitor,
saturable reactor and diode provide commutation circuit for the Morgan
chopper.
|
7
|
Comment on the value of the inductance for pre saturation and post
saturation of the saturable reactor.
|
|
The value of
inductance before saturation of the saturable reactor is high whereas its
value is low post saturation.
|
8
|
How many thyristors the load commutated chopper consists of?
|
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Four
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9
|
Describe the advantages of the load commutated chopper.
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|
Advantages
- No commutating
inductor requires
- No noise
- Less costly
- Low weight
- It can operate
at high frequency therefore minimum requirement of filter
- Commutates any
amount of current
|
10
|
Describe the disadvantages of the load commutated chopper.
|
|
Disadvantages
- High switching
losses at high frequency
- Low efficiency
in high power applications
- The peak
voltage is twice the supply voltage but it can be reduced by filtering
- The voltage
across freewheeling diode is twice the supply voltage therefore fast recovery
diode must be used.
|
11
|
Explain the term : Multi phase chopper
|
|
Multi
phase chopper
- It is a
chopper which consists of two or more than two choppers operating at same
frequency and proper phase shift
|
12
|
Describe the operating modes of the multi phase choppers.
|
|
Operating
mode of the choppers
- Phase shift
mode
- In phase mode
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13
|
Describe the function of source filter in the chopper circuit.
|
|
Function
of source LC filter in the chopper circuit
The LC filter
is connected between supply source and chopper. The LC filter reduces
- Harmonics
- Source voltage
fluctuation
- Signal
interference
- Supply
distortion
|
14
|
State the application of the DC Choppers.
|
|
Applications
- Marine hoists
- Speed control
of induction motor
- Traction motor
control
- Battery
operated vehicles
- Trolley car
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