Line side harmonics of unbalanced AC/DC converter in transient and steady state

Abstract

Harmonics analysis of AC/DC converters have been usually investigated for line-commutated rectifier and in the steady state of the controlled DC drive. In this paper, PWM rectifiers and transient states of the drive, in case of unbalanced supply are included. The mathematical model of complete DC drive have been developed and used in analysis. The results show increase of individual and total harmonic distortion in case of unbalance. The same is with transient states, in which harmonics reach high values exceeding harmonics limits stipulated by harmonic limitation standard.