A method for black starting a wind turbine and a wind farm following islanding operation, a method for restoring the wind farm following the islanding operation, and the wind turbine and wind farm. The wind turbine comprises auxiliary equipment, a generator, a converter electrically connectable to the generator, and an energy storage system, the generator is electrically connectable to the auxiliary equipment via the converter, the energy storage system is electrically connectable to the auxiliary equipment. The method for black staring the wind turbine including: measuring wind blowing smoothness degree; selecting a first power source to supply first power to the auxiliary equipment in V/f control mode and selecting a second power source to adjust an amount of active power and reactive power fed to the auxiliary equipment by the first power source in consideration of the amount of active power and reactive power demand suitable for powering the auxiliary equipment; and connecting the power sources to the aux