Effect of wind turbine converter control on wind power plant harmonic response and resonances

Abstract

Wind turbine harmonic emissions due to power electronics are a well-known power quality concern in wind power plants. This problem may be increased by resonances because they amplify harmonic distortion around resonance frequencies. Hence, the resonance phenomenon is widely analysed in the literature. Resonance studies usually consider wind turbines as ideal current sources, which can lead to inaccurate results. The paper explores the effect of wind turbine converter control on wind power plant harmonic response. It contributes expressions of wind turbine equivalent harmonic impedance including current control of the grid side converter. This impedance allows wind turbine converter control to be considered in wind power plant modelling to analyse its effect on harmonic response and resonances. PSCAD and Matlab/Simulink simulations were performed to validate the analytical expressions and illustrate the usefulness of the work in predicting harmonic distortions at WT terminals in actual WPPs.