Saturday, May 28, 2011
Power Electronics Questions [ Unit 2]
1) what is conductivity modulation of the drift layer in power diode?
2) What is reverse recovery period of the diode?
3) Explain how schottky diodes have higher switching frequency than other power diode?
4) What are the differences between AC regulators and cyclo converters?
5) What are the differences between SCR and BJT?
6) Explain thyristor characteristics and its various modes of operation.
7) Explain forward blocking mode of an thyristor.
8) Which are the two important current flowing through the thyristor?
9) Which are the different ways to turn on the thyristors?
10) Which circuit is used for transient voltage protection and explain how it works.
11) Name the different thyristor firing circuits?
12) Which type of turn on mechanism is preferred as the best amongst all?
13) which are the different types of controlled rectifier circuits?
14) In which quadrant does the single phase full converters operate?
15) Why should we go for di/dt protection?
16) Define turn on time for the thyristor turn on operation?
17) What does the equivalent circuit of thyristor comprise of?
18) How does the alpha(current gain) vary with emitter current for a thyristor?
19) Which are the ways by which we can model the thyristor so that it explains its working?
20) What is the relation between the holding current and latching current?