Power Electronics Interview Questions and Answers
In this page, we had collected Various Power Electronics and Drives related Interview questions, Viva Questions. We are appending the new Q & A whenever we are getting from readers. Some of the questions are asked to Experienced candidates based on their previous experience. If it is not related to your field, just ignore it.
[Q] What is AC voltage controller?
It is defined as the power electronics converter which converts the fixed AC voltage into a variable AC voltage without change in the frequency.
[Q] What is inverter?
A device which converts dc power into ac power at desired output voltage and frequency is called as Inverter.
[Q] What are the types of inverter?
Voltage Source Inverter
Current Source Inverter
[Q] What is chopper?
A dc Chopper is equivalent to the transformer in ac circuit. It is a static switch used to get the variable dc voltage from a constant dc voltage.
[Q] What is step down chopper?
In step down chopper, the average output voltage is less than the input supply voltage. It is also known as Buck converter.
The average output voltage VO = D . VS
[Q] What is step up chopper?
In step up chopper, the average output voltage is more than the input supply voltage. It is also known as Boost converter.
The average output voltage VO = VS / 1 - D
[Q] What is voltage commutation?
The process of a charged capacitor momentarily reverse biases the conducting SCR and turns it off is called as voltage commutation.
[Q] What is current commutation?
The process of a current pulse is made to flow in the reverse direction through the conducting SCR and thus made the net SCR current becomes zero, consequently turn off the SCR is called as current commutation.
[Q] What are the advantages of current commuted chopper?
The advantages of current commutated chopper is;
1. Commutation is reliable as load current is less than the peak commutation current
2. The auxiliary SCR is naturally commutated as its current passes through zero value.
3. The capacitor always remains charged with the correct polarity.
[Q] What is load commutation?
In load commutation, the load current flowing through the thyristor either becomes zero or is transferred to another device from the conducting SCR.
[Q] What is meant by pulse triggered devices?
As the name indicates, to trigger these devices just a pulse is sufficient. Continuous gate voltage of entire on time is not required. The advantage of pulse triggering is, it will avoid the hard triggering. Ex. Thyristor, GTO
[Q] What is meant by level-sensitive devices?
Some of the level sensitive devices are
In order to keep in the ON state condition, we need to apply continuous gate current/voltage to these devices.
[Q] What is meant by GTO?
It is a three terminal, four layer PNPN Power Semiconductor device that can be turned on by a positive gate current and can be turned off by a reverse gate current.
[Q] What are the types of GTO?
[Q] What does 10V AC mean? Is it the RMS voltage or Peak voltage or Average voltage?
In general, AC voltages and currents are mentioned in RMS values only. It is sensible to compare with steady DC voltages and currents.
For example 230V AC supply means, 230Vrms AC Supply.
[Q] What are the advantages of IGBT over BJT, MOSFET?
- Lower turn on and turn off times than BJT
- lower on state conduction losses than MOSFET
- Excellent safe operating area
More Interview Questions:
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|Basic Power Electronics Interview Questions: Set - 3|
|Power Electronics Basic Interview Questions: Set - 4|