METHOD FOR CONNECTING A POWER TRANSFORMER TO AN ELECTRICAL GRID

A method for connecting a power transformer, located between an inverter of a wind turbine and an electrical grid to the electrical grid; the method comprises the steps gradually increasing a voltage at a primary side, of the transformer from a low starting voltage to a target voltage equal or close to a nominal voltage of the transformer, by means of the inverter of the wind turbine or by means of an auxiliary inverter, thereby increasing the voltage at a secondary side of the transformer wherein the gradually increasing of the voltage uses energy of an internal energy storage device, connecting the secondary side of the transformer to the electrical grid after predefined target conditions have been reached.