Question

A $3-\varphi$ inverter with dc supply of 200 V is operating in ${120}^{\circ }$ conduction mode. The rms value of fundamental component of output line voltage is ____ V.

• A. 135.05

Answer 1

The correct option is A 135.05

In ${120}^{\circ }$ conduction mode of $3-\varphi$ VSI, Fourier analysis of output line voltage is,

$V_{ab}=\sum _{n=6K\pm 1}^{\infty }\frac{3V_s}{n\pi }(\omega t+\frac{\pi }{3})$

$whereK=1,2,3,...$

$V_{1(L-L)}=\frac{3V_s}{\pi }\sin (\omega t+\frac{\pi }{3})$

$V_{1rms}=\frac{3\times V_s}{\sqrt{2}\pi }=\frac{3\times 200}{\sqrt{2}\times \pi }=135.05V$