Question

A three-phase bridge inverter delivers power to a resistive load from a 450 V dc source. A star connected load of $10\Omega$ per phase is connected. When inverter is operated in ${180}^{\circ }$ mode, load power in kW is

Answer 1

$V_{\text{line}}=V_s\sqrt{\frac{2}{3}}V$
$V_{\text{phase}}=\frac{V_s\sqrt{2}}{3}V$

$V_{\text{phase}}=\frac{450\sqrt{2}}{3}=212.13V$

$I_{\text{phase}}=\frac{V_{\text{phase}}}{R}=\frac{212.13}{10}=21.12A$
$P=3I_{\text{phase}}^2\times R$
$=3\times (21.21{)}^2\times 10=13.5kW$