Question

A three phase full converter feeds a resistive load of $15\Omega$. For a firing angle delay of ${75}^o$, the load absorbs $6kW$.
The maximum per phase input supply voltage is ____ $V$.

Answer 1

$V_{0,rms}=\frac{V_{mL}}{\sqrt{\frac{2\pi }{3}}}{[(\frac{2\pi }{3}-\alpha )+\frac{1}{2}sin(\frac{2\pi }{3}+2\alpha )]}^{1/2}$
$V_{0,rms}=V_{mL}\frac{0.5342}{\sqrt{\frac{2\pi }{3}}}$
$V_{0,rms}=V_{mL}0.3691=\sqrt{6000\times 15}$
$V_{mL}=\frac{300}{0.3691}$
$V_{m,ph}=469.26V$