Interview Questions.

Question 1. What Are The Different Types Of Thyristor Protection?

Answer :

For dependable operation of SCR, it have to be operated in the particular scores.
SCRs are very sensitive devices and in order that they ought to be included in opposition to extraordinary running situations.
Various protection of SCR is

di/dt Protection
dv/dt Protection
Over voltage Protection
Over Current Protection
Question 2. Explain Briefly About Di/dt Protection?

Answer :

di/dt is the price of exchange of modern-day in a tool.
When SCR is forward biased and is became ON by means of the gate signal, the anode modern flows.
The anode modern calls for some time to unfold inside the tool. (Spreading of charge providers)
But if the price of upward push of anode modern-day (di/dt) is extra than the unfold pace of fee carriers then neighborhood hot spots is created close to the gate because of increased current density. This localized heating can also harm the tool.
Local spot heating is prevented via ensuring that the conduction spreads to the whole region very swiftly. (OR) The di/dt fee have to be maintained underneath a threshold (restricting) fee.
This is carried out by using connecting an inductor in collection with the thyristor.
The inductance L opposes the excessive di/dt versions.
When the present day variation is high, the inductor smooths it and protects the SCR from harm. (Though di/dt version is high, the inductor ‘L’ smooths it because it takes some time to price). L ≥ [Vs / (di/dt)]
dv/dt Protection:-

dv/dt is the fee of price of voltage in SCR.
We understand that iC=C.Dv/dt. Ie, whilst dv/dt is excessive, iC is excessive.
This high modern(iC) can also turn ON SCR even when gate modern-day is zero. This is known as as dv/dt flip ON or false flip ON of SCR.
To guard the thyristor in opposition to fake flip ON or in opposition to high dv/dt a “Snubber Circuit” is used.
Electronic Circuits Interview Questions
Question three. What Is Ac Voltage Controller?

Answer :

It is defined as the electricity electronics converter which converts the constant AC voltage right into a variable AC voltage without exchange within the frequency.

Question 4. What Is Inverter? What Are The Types Of Inverter?

Answer :

A tool which converts dc strength into ac energy at favored output voltage and frequency is referred to as as Inverter.

Inverters are extensively categorised into

Voltage Source Inverter (VSI)
Current Source Inverter (CSI)
Power Electronics Tutorial
Question 5. What Is Chopper?

Answer :

It is equivalent to a dc transformer in ac circuit. The Chopper is a static switch that is used to get the variable dc output voltage from a regular dc enter voltage.

Step down chopper:

In this circuit, the average output voltage [VO = D. VS] is much less than the enter supply voltage. It is also known as Buck converter.

Step up chopper:

It is also known as Boost converter. Here the average output voltage [VO = VS / 1 – D]  is greater than the enter deliver voltage.

Digital Electronics Interview Questions
Question 6. What Is Load Commutation?

Answer :

In load commutation, the burden modern-day flowing through the thyristor both becomes 0 or is transferred to any other tool from the engaging in SCR.

Question 7. What Is Meant By Pulse Triggered Devices?

Answer :

As the name indicates, to trigger these devices just a pulse is enough. Continuous gate voltage of entire on time isn't always required. The gain of pulse triggering is, it will avoid the hard triggering.

Ex. Thyristor, GTO

Electrical Engineering Interview Questions
Question eight. What Is A Level-touchy Device? Give Some Examples?

Answer :

Some of the level sensitive devices are

MOSFET
IGBT
MCT
IGCT
In order to maintain these devices inside the ON country situation, we should observe gate present day/voltage constantly to those devices.

Question nine. What Are The Types Of Gto?

Answer :

Asymmetrical GTO
Symmetrical GTO
Power Electronics Interview Questions
Question 10. What Does 10v Ac Mean? Is It The Rms Voltage Or Peak Voltage Or Average Voltage?

Answer :

In wellknown, AC voltages and currents are noted in RMS values simplest. It is sensible to compare with regular DC voltages and currents.

For instance 230V AC supply manner, 230Vrms AC Supply.

Question eleven. When We Have To Connect The Scrs In A Parallel Manner?

Answer :

To meet the high present day call for we can join the SCRs in a parallel manner.

Similarly to meet the excessive voltage call for we ought to join the SCRs in series.

Electronic Communications Interview Questions
Question 12. Define Gate Charge In Mosfet?

Answer :

The gate rate is described as the amount of price required for the tool throughout flip-on and turn-off time. It is the most important parameter we must don't forget at the same time as choosing the MOSFET. The switching velocity of the MOSFET depends on the rate at which the gate motive force can fee or discharge the enter gate fee.

Electronic Circuits Interview Questions