A 3-phase fully controlled bridge converter with free wheeling

A 3-phase fully controlled bridge converter with free wheeling diode is fed from 400 V, 50 Hz AC source and is operating at a firing angle of 60°. The load current is assumed constant at 10 A due to high load inductance. The input displacement factor (IDF) and the input power factor (IPF) of the converter will be

1. IDF = 0.867IPF = 0.828
2. IDF = 0.867IPF = 0.552
3. IDF = 0.5 IPF = 0.478
4. IDF = 0.5 IPF = 0.318

For 3-φ full-wave converter,
RMS value of source current,
RMS value of nth harmonic current,

I_Sh =	4I₀	sin	nπ
	√2 nπ		3

For fundamental component,

I_S1 =	2 √2	I₀ sin	π	=	√6	I₀
	π		3		π

Then, CDF (current displacement factor)

and input displacement factor, (IDF) cos α = cos 60° = 0.5
Input power factor, IPF = IDF × CDF = 0.5 × 0.955 ≅ 0.478