In a single-phase full-wave bridge circuit and in a three-phase, delta full-wave bridge circuit, what will be the ripple voltage frequency respectively?

Question

Question

This question was previously asked in

BPSC AE Paper 6 (Electrical) 25 Mar 2022 Official Paper

Answer 1

Concept:

Ripple frequency of three-phase full-wave converter:

Figure: output voltage waveform of three-phase full-wave rectifier.

From the above output voltage waveform, we can observe that for a complete one cycle of input supply we got 6 pulses in the output.

So, the three-phase full-wave ac to dc converter is a 6-pulse converter.

Then the ripple frequency of the output f₀ = m × f

Where,

m = number of pulses in the output per one complete cycle of the input

f = supply voltage frequency

Solution:

For single-phase full-wave bridge circuit f0 = 2 × f

For a three-phase full-wave converter f₀ = 6 × f

Hence, the ratio output ripple-frequency to the supply-voltage frequency = f0 / f = 6