Managing Harmonics in Wind Power Plants Using the Control of Wind Turbines

The integration of wind power in electricity generation introduces challenges on power quality issues. This paper proposes an algorithm to mitigate the harmonic distortion at the point of connection (PoC) of a wind power plant (WPP). Instead of opting to conventional method using passive filters to mitigate harmonics, this method only upgrades the control functions of the existing control systems of a WPP without additional investment. The mitigation algorithm performs the measurements at the PoC for a time window, which is transformed and analysed in frequency-domain. Then, it calculates the required harmonic current injections for selected wind turbine(s) to cancel the harmonics at PoC based on the frequency-dependent nodal analysis. To validate the algorithm, a generic WPP layout with multiple strings and field measurements of harmonic emission provided by Vestas Wind System A/S is used to simulate the harmonic propagation in the WPP using the MATLAB/Simulink along with PLECS Toolbox.