Wind farm black start

A method of performing a black start in a wind farm, the wind farm comprising a primary black start enabled wind turbine, at least one secondary black start enabled wind turbine, and a wind farm grid interconnecting at least a part of the wind turbines in the wind farm, the method comprising;

• starting the primary black start enabled wind turbine in black start mode in order to supply voltage to the wind farm grid;
• monitoring, at the at least one secondary black start enabled wind turbine, an electric parameter value in the wind farm grid;
• and
• starting the at least one secondary black start enabled wind turbine in black start mode in order to supply voltage to the wind farm grid when the electric parameter value meets a predetermined condition;
• and
• wherein the electric parameter value is a code modulated onto the grid voltage, and wherein the predetermined condition is met when the code corresponds to a predetermined code.