Research on Harmonic Suppression Strategy of SVG Based on Active Disturbance Rejection Control

As AC submarine cables are adopted to connect offshore wind farms to the onshore power grid, severe harmonic problems and the deterioration of power quality may be induced. To address the issue of excessive harmonics in the offshore wind farms, this paper applies the active disturbance rejection control (ADRC) to static var generators (SVG) for harmonic suppression. Firstly, the model of SVG is established, and the harmonic propagation mechanism is analyzed. Secondly, the SVG voltage outer loop controller is designed based on the ADRC. On this basis, the system transfer function model is deduced, and the operational stability and harmonic suppression capability of ADRC are theoretically studied by using the frequency domain characteristic curve. Finally, the MATLAB/Simulink model of Jiangsu's offshore wind power plant is built to verify the effect of ADRC strategy on harmonic suppression. Simulative results show that the ADRC can effectively suppress the harmonics occurred in offshore wind farms, and the suppression performance is not affected by the operating conditions, and has strong robustness.