Abstract: Provided is a method for controlling an electric generator of a wind turbine. The method includes varying an amplitude and/or phase angle of an harmonic current of said electric generator, while said electric generator is rotating, in particular at a known condition, measuring a signal indicative of generator vibration after and/or during varying said amplitude and/or phase angle, repeating said varying and said measuring until a predetermined requirement is met, evaluating an operating point for said electric generator by using said measured signals indicative of generator vibration in order to reduce a ripple torque of said generator, and controlling a current, in particular said harmonic current, of said electric generator in order to meet said operating point.

Abstract: Provided is a method for controlling an electric generator of a wind turbine. The method includes varying an amplitude and/or phase angle of an harmonic current of said electric generator, while said electric generator is rotating, in particular at a known condition, measuring a signal indicative of generator vibration after and/or during varying said amplitude and/or phase angle, repeating said varying and said measuring until a predetermined requirement is met, evaluating an operating point for said electric generator by using said measured signals indicative of generator vibration in order to reduce a ripple torque of said generator, and controlling a current, in particular said harmonic current, of said electric generator in order to meet said operating point.

Abstract: A tower segment, in particular for a tower of a wind turbine, a wind turbine, and a method for manufacturing a tower segment is provided. A tower segment, in particular for a tower of a wind turbine, comprising a casing segment with an inner casing surface, an outer casing surface and a cutout for a door, wherein the inner casing surface has a first inner reinforcing portion and/or the outer casing surface has an outer reinforcing portion, wherein the inner reinforcing portion and/or the outer reinforcing portion adjoin the cutout, and the inner reinforcing portion has an inner reinforcing plate and/or the outer reinforcing portion has an outer reinforcing plate.

Abstract: A tower segment, in particular for a tower of a wind turbine, a wind turbine, and a method for manufacturing a tower segment is provided. A tower segment, in particular for a tower of a wind turbine, comprising a casing segment with an inner casing surface, an outer casing surface and a cutout for a door, wherein the inner casing surface has a first inner reinforcing portion and/or the outer casing surface has an outer reinforcing portion, wherein the inner reinforcing portion and/or the outer reinforcing portion adjoin the cutout, and the inner reinforcing portion has an inner reinforcing plate and/or the outer reinforcing portion has an outer reinforcing plate.