The present invention describes an electric generator (11) for a wind turbine (1) comprising a stator (20) or rotor (30), the stator (20) or rotor (30) having plurality of winding systems (41, 42, 43, 44), each winding system (41, 42, 43, 44) covering a respective angular portion of the stator (20) or rotor (30) about an axis of rotation (Y) of the electric generator (11), and a controller (50) for controlling the current flowing in the winding systems (41, 42, 43, 44). The controller (50) is configured for receiving or determining a thickness of an airgap (10) between the stator (20) and the rotor (30) and controlling the current flowing in at least one of the winding systems (41, 42, 43, 44) so that a respective magnetic radial force is generated, the magnetic radial force acting on the stator (20) and/or rotor (30) for increasing the airgap (10) where the airgap (10) is below a threshold airgap value.