Frequency domain analysis for multiple controlled rectifiers

Harmonic studies of power rectifiers usually make simplifying assumptions about overlap angle and DC ripple current to enable the waveforms to be analysed more easily. The author uses these simplifications to compute an initial estimate of the AC line current harmonics and then uses that estimate to calculate all the DC side harmonics with the aid of both a voltage switching function and a corresponding current switching function. The method can be extended to two or more rectifiers on a common AC bus where the commutation notches on one bridge affect the DC current in the other one, and to more complex switching systems such as twelve pulse rectifiers