Offshore Wind Farm Power Control Using HVdc Link

In this paper, a method is presented to control offshore wind farm output power. This method is able to fix the wind farm output power even during wind speed variations. In the proposed method, the offshore wind farm is connected to the onshore grid through the high-voltage dc (HVdc) cable. Moreover, the power control of the wind turbines is achieved by controlling the HVdc convertors. In the proposed system, the generator side convertors have to control the active power absorbed from the wind, and the grid side ones are obtained to control the HVdc link voltage. The control system is based on applying the appropriate modulation index to the voltage source converters. Two control strategies are proposed and analyzed to control wind farm output power. The simulation results illustrate that the proposed method is able to smooth the output power of the offshore wind farms appropriately. The proposed wind farm configuration and the control system are validated by simulations in the MATLAB/Simulink environment.