The 3-phase modulating waveforms  and , used in sinusoidal PWM in a Voltage Source Inverter (VSI) are

where  is the fundamental frequency. The modulating waveforms are compared with a 10 kHz triangular carrier whose magnitude varies between +1 and -1. The VSI has a DC link voltage of 600 V and feeds a star connected motor. The per phase fundamental RMS motor voltage, in volts, is closest to

A 3-phase grid-connected voltage source converter with DC link voltage of 1000 V is switched using sinusoidal Pulse Width Modulation (PWM) technique. If the grid phase current is 10 A and the 3-phase complex power supplied by the converter is given by (−4000 − 𝑗3000) VA, then the modulation index used in sinusoidal PWM is ___________. (round off to two decimal places)

A 3-phase voltage source inverter is supplied from a 600V DC source as shown in the figure below. For a star connected resistive load of  per phase, the load power for 120° device conduction, in kW, is ___________.  

A three-phase voltage source inverter with ideal devices operating in 180° conduction mode is feeding a balanced star-connected resistive load. The DC voltage input is . The peak of the fundamental component of the phase voltage is

A three-phase voltage source inverter (VSI) as shown in the figure is feeding a delta connected resistive load of /phase. If it is fed from a 600V battery, with  conduction of solid-state devices, the power consumed by the load, in kW, is_____________.

In the 3-phase inverter circuit shown, the load is balanced and the gating scheme is conduction mode. All the switching devices are ideal.

The RMS value of load phase voltage is

In the 3-phase inverter circuit shown, the load is balanced and the gating scheme is conduction mode. All the switching devices are ideal.

If the dc bus voltage, the power consumed by 3-phase load is

A 3-phase Voltage Source Inverter is operated in 180° conduction mode. Which one of the following statements is true?

The output voltage waveform of a three-phase square-wave inverter contains

An inverter has a periodic output voltage with the output waveform as shown in Fig. When the conduction angle α=120°, the RMS fundamental component of the output voltage is

Figure shows an inverter circuit with a dc source voltage. The semiconductor switches of the inverter are operated in such a manner that the pole voltages and are as shown in Figure. What is the RMS value of the pole-to-pole voltage?

A three phase voltage source inverter supplies a purely inductive three phase load. Upon Fourier analysis, the output voltage waveform is found to have an n-th order harmonic of magnitude  times that of the fundamental frequency component. The load current would then have an n-th order harmonic of magnitude

An inverter capable of supplying a balanced three-phase variable voltage variable frequency output is feeding a three-phase induction motor rated for 50Hz and 440V. The stator winding resistances of the motor are negligible small. During starting, the current inrush can be avoided without sacrificing the starting torque by suitably applying:

Match the output wave forms:

(P) Single phase fully controlled ac-dc converter

(Q) Voltage commutated dc-ac chopper (E=input dc Voltage)

(R) Phase voltage of a star connected balanced three-phase load fed from a three-phase inverter with 180° Conduction. (input dc voltage=E)

(S) Line voltage of a six stepped inverter with input dc voltage E

(T) Three-phase diode bridge rectifier

(A)

(B)

(C)

(D)

(E)