In a 3 phase VSI out of eight valid states, the number of valid states that produce zero ac line voltages is/are_________?

Related Mcqs:

1. In square wave operation mode of 3 phase VSI, the VSI

   A. Can control the load voltage
   B. Cannot control the load voltage
   C. Cannot control the load voltage except by means of dc link voltage
   D. Cannot control the load voltage except by means of dc link current

2. In a 3 phase CSI, if the required line output voltages are balanced and 120 degree out of phase, then the chopping angles are used to eliminate only the harmonics at frequencies

   A. 5
   B. 7
   C. 11
   D. All of these

3. For commutation in three phase PAC, normally balanced three phase voltages VR, VY and VB are connected to the three legs of the converter via______________?

   A. Three inductances
   B. Three capacitances
   C. Three resistance
   D. Three transistors

4. The square wave operation of 3 phase VSI lines contains the harmonics. The amplitudes are____________?

   A. Directly proportional to their harmonic order
   B. Inversely proportional to their harmonic order
   C. Not related to their harmonic order
   D. None of these

5. In single phase VSI, the harmonic which is not present is____________?

   A. 2nd
   B. 3rd
   C. 5th
   D. 7th

6. Single phase VSI are mainly used in___________?

   A. Power supplies
   B. Ups
   C. Multilevel configuration
   D. All of these

7. In a 3 phase VSI SPWM to use a single carrier signal and preserve the features of PWM technique, the normalized carrier frequency should be____________?

   A. Multiple of two
   B. Odd multiple of three
   C. Odd multiple of five
   D. Odd multiple of seven

8. Under harmonic free load voltages, the 3 phase VSI_____________?

   A. Does not contains second harmonic
   B. Does not contains third harmonic
   C. Does not contains fifth harmonic
   D. Does not contains seventh harmonic

9. 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

10. The ac output voltage waveform of VSI and AC output current waveform of CSI respectively is composed of___________?

    A. High dv / dt, low di / dt
    B. Low dv / dt, low di / dt
    C. Low dv / dt, high di / dt
    D. High dv / dt, high di / dt