Question

A 3-$\varphi$, full converter feeds a load with ripple free DC current $I_o$. If source inductance of 415 V, 50 Hz supply is 10 mH with firing delay angle of 30° and overlap angle of 8°. The value of $I_o$ is

• A. 7.287 Amp
• B. 4.858 Amp
• C. 2.429 Amp
• D. 5.152 Amp

Answer 1

The correct option is A 7.287 Amp

For $3-\varphi$ converter,

$cos(\alpha +\mu )=cos\alpha -\frac{2\omega L_s{I}_0}{V_{ml}}$

$I_0=\frac{V_{ml}}{2\omega L_s}[cos\alpha -cos(\alpha +\mu \left)\right]$
$=\frac{425\sqrt{2}}{2\times 100\pi \times 10\times {10}^{-3}}\left[cos\right({30}^o)-cos({38}^o\left)\right]=7.287Amp$