Analyzing input harmonic currents of a six-pulse AC/DC converter by an efflicient time-domain approach

This paper presents an efficient approach for analyzing harmonic currents generated by a six-pulse ac/dc converter in steady state. The approach is carried out in time-domain and the interactions between the system and the converter are considered in the study. In calculating harmonic currents generated by the converter, the Poincare map based approach is applied to increase the computational efficiency and solution accuracy. The computed ac-side harmonic components of the converter current are then extracted via FFT. Solutions obtained by the proposed method are compared with those obtained by using a brute force time-domain simulation tool, Simulink of Matlab. It is shown that the harmonic currents determined by the proposed approach well agree with those obtained by the simulation tool, but the solution time is significantly reduced. In addition, the proposed method also can be applied to analyze harmonic currents produced by other types of power-electronic devices operating periodically.