Inverters · Power Electronics · GATE EE

The RMS value of the fundamental component of $${v_0}\left( t \right)$$ in volts is ___________.

The proper configuration for realizing switches $${S_1}$$ to $${S_6}$$ is

Consider the single-phase voltage source inverter circuit feeding an inductive load (L). Assume that the power MOSFET switches are ideal. $\mathrm{S}_1$ and $\mathrm{S}_2$ are switched on during the first $10 \mu \mathrm{~s}$, and $\mathrm{S}_3$ and $\mathrm{S}_4$ are switched on during the next $10 \mu \mathrm{~s}$ in a switching cycle. The switches in the same leg are thus switched in a complementary fashion. Neglect the dead time. The waveform of the inductor current ( $i_L$ ) in the steady state is triangular with a peak value of 5 A as shown.

The rms value of the current through the switch $S_1$ is

The 3-phase modulating waveforms $\left(v_a(t), v_b(t), v_c(t)\right)$, used in sinusoidal PWM in a voltage source inverter (VSI) are

$$ \begin{aligned} & v_a(t)=0.8 \sin (\omega t) \vee \\ & v_b(t)=0.8 \sin \left(\omega t-\frac{2 \pi}{3}\right) \vee \\ & v_c(t)=0.8 \sin \left(\omega t+\frac{2 \pi}{3}\right) \vee \end{aligned} $$

where $\omega=2 \pi \times 40 \mathrm{rad} / \mathrm{s}$ 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 single-phase full bridge voltage source inverter (VSI) feeds a purely inductive load. The inverter output voltage is a square wave in 180° conduction mode. The fundamental frequency of the output voltage is 50 Hz. If the DC input voltage of the inverter is 100 V and the value of the load inductance is 20 mH, the peak-to-peak load current in amperes is ________ (rounded off to the nearest integer).

Consider an ideal full-bridge single-phase DC-AC inverter with a DC bus voltage magnitude of 1000 V. The inverter output voltage v(t) shown below, is obtained when diagonal switches of the inverter are switched with 50% duty cycle. The inverter feeds a load with a sinusoidal current given by, $$i(t) = 10\sin \left( {\omega t - {\pi \over 3}} \right)A$$, where $$\omega = {{2\pi } \over T}$$. The active power, in watts, delivered to the load is __________. (round off to nearest integer).

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 rid 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 single-phase full bridge inverter fed by a 325 V DC produces a symmetric quasi-square waveform across " $a b$ " as shown. To achieve a modulation index of 0.8 , the angle $\theta$ expressed in degrees should be $\_\_\_\_$ . (Round off to 2 decimal places)

(Modulation index is defined as the ratio of the peak of the fundamental component of $V_{d b}$ to the applied DC value)

If the load current is sinusoidal and is zero at $$0,\,\,\pi ,2\pi ....,$$ the node voltage $${V_{AO}}$$ has the waveform

Appropriate transition $$i.e,,$$ $$Zero$$ voltage switching $$(ZVS)/Zero$$ current switching $$(ZCS)$$ of the $$IGBTs$$ during turn - on/turn off is

In the interval when $${V_0} < 0$$ and $${i_0} > 0$$ the pair of devices which conducts the load current is

The $$rms$$ value of load phase voltage is

If the $$dc$$ bus voltage $${V_d} = 300\,\,V,$$ the power consumed by $$3$$-phase load is

The inverter is operated at $$50$$ $$Hz$$ in $${180^0}$$ square wave mode. Assume that the load current does not have any $$dc$$ component. The peak value of the inductor current $${i_0}$$ will be

When the conduction angle $$\alpha = {120^0},$$ the $$rms$$ fundamental component of the output voltage is

With reference to the output waveform given in figure, the output of the converter will be free form $${5^{th}}$$ harmonic when

$$(P)$$ 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 $${180^ \circ }$$ conduction (input $$dc$$ voltage=$$E$$)
$$(S)$$ Line voltage of a six stepped inverter with input dc voltage $$E$$
$$(T)$$ Three-phase diode bridge rectifier.