PYQs Based test 23: Power Electronics

A three-phase diode bridge rectifier is feeding a constant DC current of $100A$ to a highly inductive load. If three-phase, $415V,50Hz$ AC source is supplying to this bridge rectifier then the rms value of the current in each diode, in ampere, is _____________.

The waveform of the current drawn by a semi-converter from a sinusoidal AC voltage source is shown in the figure. If I₀ = 20 A, the rms value of fundamental component of the current is ___________A (up to 2 decimal places).

The figure shows the circuit of rectifier fedfrom a 230V (rms), 50Hz sinusoidal voltage source. If we want to replace the current source with a resistor so that the rms value of the current suppliedby the voltage source remains unchanged the value of resistance (in ohms) is ------ (Assume diodes to be ideal)

The single-phase full-bridge voltage source inverter (VSI), shown in figure, has an output frequency of $50Hz$. It uses unipolar pulse width modulation with switching frequency of $50kHz$ modulation index of 0.7. For $V_{in}=100V$ DC, $L=9.55mH,C=63.66\mu F$, and $R=5\Omega$, the amplitude of the fundamental component in the output voltage $V_0$ (in volt) under steady-state is ___________.

In the dc-dc converter circuit shown, switch Q is switched at a frequency of 10 kHz with a duty ratio of 0.6. All components of the circuit are ideal, and the initial current in the inductor is zero. Energy stored in the inductor in mJ (rounded off to 2 decimal places) at the end of 10 complete switching cycles is ________