In a full bridge VSI, in order to avoid the short circuit across the DC bus and the undefined AC output voltage condition, the modulating technique should ensure that___________?

In a full bridge VSI, in order to avoid the short circuit across the DC bus and the undefined AC output voltage condition, the modulating technique should ensure that___________?

A. Top switch of each leg is on at any instant
B. Bottom switch of each leg is on at any instant
C. Either A. or B.
D. None of these

In variable frequency, PWM gain

In variable frequency, PWM gain

A. Phase lead helps to increase the phase margin of the control loop
B. Phase lag helps to increase the phase margin of the control loop
C. Phase lead helps to decrease the phase margin of the control loop
D. Phase lag helps to decrease the phase margin of the control loop