Recent activity in Power Electronics

Consider the circuit shown. Assume that the diode ( $D$ ) is ideal.Given $v_{s}=100 \sin (2 \pi 50 t) \mathrm{V}, V_{d c}=50 \mathrm{~V}$, and $R=10 \Omega$, the average ...

Consider the boost converter circuit shown. Assume that the semiconductor devices are ideal. In steady state, the inductor current rises linearly from $0$ A to $6$ A in t...

Consider the single-phase voltage source inverter circuit feeding an inductive load $(L)$. Assume that the power MOSFET switches are ideal. $S_{1}$ and $S_{2}$ are switch...

Consider the circuit shown. Assume that the diode $D$ is ideal. The supply voltage $v_{s}=325 \sin (2 \pi 50 t) \mathrm{V}, L=500 ~\mu \mathrm{H}$, and $R=10 ~\Omega$. Th...

Consider the circuit shown in Figure (a). A gate pulse $v_{g}$ is applied between time instants $t_{0}$ and $t_{1}$. After $t_{1}$, during the $\text{MOSFET}$ turn $\text...

The figure shows a straight-line approximation for the forward characteristics of a power diode. A continuous on-state current of $15 ~\text{A}$ is flowing through the di...

Consider an ideal full-bridge single-phase $\text{DC-AC}$ inverter with a $\text{DC}$ bus voltage magnitude of $1000$ $\text{V}$. The inverter output voltage $v\left ( t ...

Thyristor $T_{1}$ is triggered at an angle $\alpha$ (in degree), and $T_{2}$ at angle $180^{\circ}+\alpha$, in each cycle of the sinusoidal input voltage. Assume both thy...

The voltage at the input of an $\text{AC-DC}$ rectifier is given by $v\left ( t \right ) = 230 \sqrt{2} \sin \omega t$ where $\omega = 2\pi \times 50$ rad/s. The input cu...

In the circuit shown in the figure, the diode used is ideal. The input power factor is ________. (Give the answer up to two decimal places).

The operating region of the developed torque $\left(T_{e m}\right)$ and speed $(\omega)$ of an induction motor drive is given by the shaded region $OQRE$ in the figure. T...

The steady state capacitor current of a conventional DC-DC buck converter, working in CCM, is shown in one switching cycle. If the input voltage is $30 \: V$, the value o...

In the following circuit, the average voltage$V_{o}=400\left(1+\frac{\cos \alpha}{3}\right) \mathrm{V}$where $\alpha$ is the firing angle. If the power dissipated in the ...

The $3$-phase modulating waveforms $\left(v_{a}(t), v_{b}(t)\right.$ and $\left.v_{c}(t)\right)$, used in sinusoidal PWM in a Voltage Source Inverter (VSI) are$$ \begin{a...

In the circuit with ideal devices, the power MOSFET is operated with a duty cycle of $0.4$ in a switching cycle with $I=10 \mathrm{~A}$ and $V=15 \mathrm{~V}$. The power ...

The input voltage $v(t)$ and current $i(t)$ of a converter are given by,$\begin{array}{l} v(t)=300 \sin (\omega t) V \\ i(t)=10 \sin \left(\omega t-\frac{\pi}{6}\right)+2...

A phase-controlled, single-phase, full-bridge converter is supplying a highly inductive $DC$ load. The converter is fed from a $230$ V, $50$ Hz, AC source. The fundamenta...

In the circuit shown, the input $V_{i}$ is a sinusoidal $\text{AC}$ voltage having an $\text{RMS}$ value of $230\;V\pm 20\%$. The worst-case peak-inverse voltage seen ac...

Consider the boost converter shown. Switch $Q$ is operating at $\text{25 kHz}$ with a duty cycle of $0.6$. Assume the diode and switch to be ideal. Under steady-state con...

Consider the buck-boost converter shown. Switch $Q$ is operating at $\text{25 kHz}$ and $0.75$ duty-cycle. Assume diode and switch to be ideal. Under steady-state conditi...

A single-phase full-bridge inverter fed by a $\text{325 V DC}$ produces a symmetric quasi-square waveform across '$ab$' as shown. To achieve a modulation index of $0.8$, ...

​​​​​If the following switching devices have similar power ratings, which one of them is the fastest?$\text{SCR}$$\text{GTO}$$\text{IGBT}$$\text{Power MOSFET}$

​​​​​A single-phase triac based $\text{AC}$ voltage controller feeds a series $\text{RL}$ load. The input $\text{AC}$ supply is $230 \mathrm{~V}, 50 \mathrm{~Hz}$. The va...

A forced commutated thyristorized step-down chopper is shown in the figure. Neglect the $\text{ON}$-state drop across the power devices. Assume that the capacitor is init...

In the $\mathrm{DC}-\mathrm{DC}$ converter shown in the figure, the current through the inductor is continuous. The switching frequency is $500 \mathrm{~Hz}$. The voltage...

A single-phase full bridge voltage source inverter $\text{(VSI)}$ feeds a purely inductive load. The inverter output voltage is a square wave in $180^{\circ}$ conduction ...

A single-phase half-controlled bridge converter supplies an inductive load with ripple free load current. The triggering angle of the converter is $60^{\circ}$. The ratio...

The chopper circuit shown in figure (i) feeds power to a $5 \text { A DC}$ constant current source. The switching frequency of the chopper is $100 ~\mathrm{kHz}.$ All the...

A semiconductor switch needs to block voltage $\text{V}$ of only one polarity $\text{(V>0)}$ duringOFF state as shown in figure (i) and carry current in both directions d...