Calculation of harmonic currents in series connected converter with AC filters under unbalanced power supply

This paper proposes an analytical method for calculating the harmonic currents of a series connected three-phase bridge controlled rectifier with AC filters under unbalanced power supply. The derivation of the analytical equations for the harmonic currents on both the DC and AC sides is given. The calculation is based on the frequency domain method and the rectifier switching functions. All of the calculations are conducted only by algebraic calculations with accuracy. The validity of the proposed method is proved by comparing with the results of simulation. This method can be also extended to any multiple converters in series.