In 60‐degrees PWM inverter power supply,

A. Power devices are made 'ON' for 1/3 of the cycle.

B. Power devices are made 'OFF' for 1/3 of the cycle.

C. The phase voltage = 0.57735 V_supply.

D. Line voltage = Vsupply.

E. Line voltage < Vsupply.

Choose the correct answer from the options given below:

Question

Question

This question was previously asked in

UGC NET Paper 2: Electronic Science 3rd Dec 2021 Shift 2

Answer 1

Pulse width modulation

qImage14750

In the given figure, 2d represents the total pulse width or the time duration for which the device is conducted in the one-half cycle (80°)

In 60-degree PWM, the device conducts for 120°.

So, the device is made 'ON' for 2/3 of the cycle. Hence, statement A is incorrect.

and the device is made 'OFF' for 1/3 of the cycle. Hence, statement B is correct.

The phase voltage is given by:

\(V_p=\sqrt{120\over 360}\space V_{supply}\)

The phase voltage = 0.57735 Vsupply

Hence, statement C is correct.

The line voltage in PWM is always less than the supply voltage.

Hence, statement E is correct.

The correct answer is option A.