Question

A three phase inverter is connected to a direct voltage source of $240V$. In ac side, the current is sinusoidal with a peak of $20A$ and current is leading the voltage by ${60}^o$, then the power flow through the inverter is ________ W.

(Assume mode of conduction is ${180}^o$ and load is star connected)

• A. 2291.88

Answer 1

The correct option is A 2291.88
Power flow through the inverter is,
$P_{avg}=3V_{pn}{I}_{ph}.cos\varphi$
Output phase voltage is having harmonics but output phase current does not have harmonics (since it is a pure sine wave), output average power does not have harmonic power
$V_{s1}=\frac{2V_s}{\pi \sqrt{2}}=\frac{2\times 240}{\pi \sqrt{2}}=108.038V$
Power flow through the inverter,
$=3\times 108.038\times \frac{20}{\sqrt{2}}\times cos{60}^o=2291.83W$