Modelling the effects of AC system impedance unbalance on PWM converters using frequency coupling matrices

This work analyzes the effect of AC system impedance unbalance on the generation of harmonics by three phase PWM voltage source converters. The investigated circuit is intended to represent a PWM interface to an electrical supply network. The effect is demonstrated by modelling the AC side impedance unbalance and the PWM converter in the frequency domain using frequency coupling matrices (FCMs).