Question

In case of sinusoidal pulse width modulation with MI < 1, the order of the dominate harmonic can be raised by

(a) increasing the number of pulses

(b) reducing the number of pulses

(c) lowering the input voltage frequency

(d) raising the input voltage frequency

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Answer 1

Right option is (a) increasing the number of pulses

To elaborate: For MI less than one, largest harmonic amplitudes in the output voltage are associated with harmonics of order 2N (+/-) 1. Thus, by increasing the number of pulses per half cycle (N), the order of the dominate harmonic can be raised.