Methodd for operating a wind turbine for powering auxiliary devices in the event of a grid fault

A method for operating a wind turbine, the wind turbine having a generator and an aerodynamic rotor with a plurality of rotor blades, the method comprising:

• generating electrical power from wind using the generator;
• using a first portion of the generated electrical power as an auxiliary power component for supplying auxiliary devices of the wind turbine that are used for operating the wind turbine, wherein the auxiliary power component is variable and has an upper auxiliary power limit;
• feeding a second portion of the generated electrical power into an electrical supply grid as a feed-in power component;
• checking the electrical supply grid for a grid fault that prevents feeding of the second portion of the generated electrical power of the wind turbine into the electrical supply grid;
• detecting the grid fault;
• and
• in response to detecting the grid fault, continuing to operate the wind turbine including at least:
• cutting back the generation of electrical power from the wind to a cut-back power, wherein the cut-back power is equivalent to the upper auxiliary power limit or is greater than the upper auxiliary power limit;
• drawing the auxiliary power component for supplying the auxiliary devices from the cut-back power;
• and
• consuming residual power of the cut-back power, the residual power being an amount of the cut-back power remaining after drawing the auxiliary power component.