Question

A single phase voltage source inverter is feeding a purely inductive load as shown in the figure

The interter is operated at 50 Hz in 180° 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

• A.
  40 A
• B.
  10 A
• C.
  20 A
• D.
  6.37 A

Answer 1

The correct option is B

10 A


Load current increases linearly from -$I_p$ to $I_p$ during $0<\omega t\le \pi .$ Where $I_P$ = Peak value of $i_0$

$\Rightarrow t_1=\frac{\pi }{\omega }=\frac{\pi }{2\pi \ast 50}=\frac{1}{100}\sec$

$Att=0,i_0=-I_{P}andt=t_1,i_0=I_P$

$V_0=L\frac{di}{dt}$

During $0<\omega t<\pi$

$V_0=V_s=200V$

$\Rightarrow 200=0.1\left(\frac{I_P-(-I_P)}{t_1-0}\right)$

$\Rightarrow 2I_P=\frac{200}{0.1}\times t_1$

$I_P=\frac{2000}{2}\times \frac{1}{100}=10A$