List of top Power Electronics and Drives Questions

The circuit shown in the figure has reached steady state with thyristor \(T\) in OFF condition. Assume that the latching and holding currents of the thyristor are zero. The thyristor is turned ON at \(t=0 \, \text{sec}\). The duration in microseconds for which the thyristor would conduct, before it turns off, is ................. (Round off to 2 decimal places). \begin{center} \includegraphics[width=0.45\textwidth]{27.jpeg} \end{center}

The single-phase rectifier consisting of three thyristors \(T_1, T_2, T_3\) and a diode \(D_1\) feed power to a 10 A constant current load. \(T_1\) and \(T_3\) are fired at \(\alpha = 60^\circ\) and \(T_2\) is fired at \(\alpha = 240^\circ\). The reference for \(\alpha\) is the positive zero crossing of \(V_{in}\). The average voltage \(V_O\) across the load in volts is ............ (Round off to 2 decimal places). \begin{center} \includegraphics[width=0.5\textwidth]{29.jpeg} \end{center}

All the elements in the circuit shown in the following figure are ideal. Which of the following statements is/are true? \begin{center} \includegraphics[width=0.65\textwidth]{21.jpeg} \end{center}

A semiconductor switch needs to block voltage $V$ of only one polarity ($V > 0$) during OFF state as shown in figure (i) and carry current in both directions during ON state as shown in figure (ii). Which of the following switch combination(s) will realize the same? \begin{center} \includegraphics[width=0.5\textwidth]{10.jpeg} \end{center}

The chopper circuit shown in figure (i) feeds power to a 5 A DC constant current source. The switching frequency of the chopper is $100 \,\text{kHz$. All the components can be assumed to be ideal. The gate signals of switches $S_{1}$ and $S_{2}$ are shown in figure (ii). The average voltage across the 5 A current source is:} \begin{center} \includegraphics[width=0.5\textwidth]{08.jpeg} \end{center}

The correct statements are:
A. A thyristor requires turn off circuit while transistor dose not.
B. The voltage drop of thyristor is less than that of a transistor.
C. A thyristor requires a continuous gate current.
D. A transistor draws continuous base current.
Choose the correct answer from the options given below:

Consider the correct statements:
A. Both voltage source inverter and current source inverter require feed back diode.
B. Only current source inverter require feedback.
C. GTO can not be used in a current source inverter.
D. Only voltage source inverter requires feedback diode.
Choose the correct answer from the options given below: