Harmonic Amplification Analysis and Suppression Method for Offshore Wind Farms

At present, the proportion of new energy access in the power system is increasing, and wind power is the key support for achieving energy security, green and low-carbon. Compared with overhead lines, power cables shows more than 20 times capacitance effect at the same voltage level. The result makes threats of the safe and reliable operation of offshore wind farms. Therefore, under AC grid connection of large-scale offshore wind farms, harmonic amplification factors and harmonic control methods are studied. Firstly, the harmonic state space model of high-voltage submarine cables and wind turbines of offshore wind farms is established. The harmonic amplification mechanism of offshore wind farms is analyzed, when they are connected to the grid. Then, harmonic suppression method with energy storage based APF (Active Power Filter) is analyzed. Finally, taking an offshore wind power grid-connected project as a case, the Simulink simulation model is built. The correctness and effectiveness of the theoretical analysis and method are verified.