Calculation of harmonic currents based on frequency domain technique in a three-phase convertor for three phase harmonic analysis of distributor networks

A practical method for calculating the harmonic currents of a three-phase bridge controlled rectifier with slightly distorted power supply under balanced and unbalanced conditions is presented in this paper. The method, based on the frequency domain technique and switching functions, takes into account the ripple components of DC current, the overlap angle and the harmonic components in the supply voltage. The harmonic currents generated by convertors with nonsinusoidal supply voltages are investigated. The algorithm presented in this paper can be used in both predicting harmonics generated by convertors and analysing the interaction between various convertor-loads along a distributor.