GRID FREQUENCY CONTROL IN AN OFFSHORE WIND FARM

A method of controlling a wind farm including a plurality of wind turbines installed in an AC subgrid, which is connected via a high-voltage rectifier and a DC line to an energy conversion device, the method including: controlling a power infeed of each wind turbine to maintain a setpoint grid frequency of the subgrid; sensing a grid frequency in the subgrid; determining a reference quantity based on a difference of the sensed grid frequency and the setpoint grid frequency; and controlling the energy conversion device in accordance with the determined reference quantity.