Question

A three-phase full converter is supplied from a three phase 230 V, 60 Hz supply. The load current is continuous and negligible ripple. The value of average load current $I_{dc}=150A$ and the commutating inductance $L_C=0.1$ mH. If the firing angle $\alpha ={10}^{\circ }$, then the overlap angle is _______

Answer 1

$V_{mph}=\frac{230\sqrt{2}}{\sqrt{3}}=187.79V$

$V_{dc}=\frac{3\sqrt{3}{V}_{mph}}{\pi }=310.61V$

$6f{L}_c{I}_{dc}=V_{dc}cos\alpha -V_{dc}cos(\alpha +\mu )$
$6\times 60\times 150\times 0.1\times {10}^{-3}=310.61[\cos \alpha -\cos (\alpha +\mu \left)\right]$

For $\alpha ={10}^{\circ }$
Overlap angle $\mu ={4.66}^{\circ }$