Influence of System Parameters on Harmonic Distortion Contributions of Renewable Power Plants

Harmonic analysis of inverters in renewable power plants can be very complex and is often only based on measurement data. This paper uses the harmonic modelling technique specified by IEC 61400-21-3 to perform a harmonic analysis on a specific inverter system and analyse the effect of grid impedance and control system parameters on harmonic distortion. Harmonic grid current distortion is often used for compliance of renewable power plants. Through impedance based arguments based on the harmonic model, this paper shows how harmonic currents, produced by the interaction between background voltage distortion and the system impedance, can decrease harmonic voltage distortion at the point of connection of a renewable power plant.