Impact of a SG nonlinear model on the harmonic distortion of a distribution generation system

In this paper the impact of a synchronous generators nonlinear model on the voltage distortion of a distributed generation system is investigated. The SGs are modelled in the harmonic domain and include the space harmonics and frequency conversion. A decoupled harmonic power flow program is used for the system harmonic study. The system nonlinear loads are modelled as decoupled harmonic current sources. Simulation results are presented for an actual 24-bus DG system including 6 distributed generators. It is shown that the SGs working under distorted conditions can inject considerable amount of current harmonics and considerably increase the level of system harmonic distortion.