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.