Patent ID: 8039980

Claim:
A wind turbine generator comprising: a wind turbine rotor having one or more wind turbine blades; an icing amount detecting unit configured to detect an icing amount on at least one wind turbine blade when the wind turbine rotor is rotating; and an operation mode switching unit configured to switch an operation mode of the wind turbine generator to any one of a normal operation mode in which the wind turbine rotor is rotated and power is generated, a no-load operation mode in which the wind turbine rotor is rotated but no power is generated, and an operation stop state in which the wind turbine rotor is stopped; wherein the operation mode switching unit switches the operation mode to the no-load operation mode if the icing amount detected by the icing amount detecting unit exceeds a first predetermined value and operation mode is the normal operation mode; and the icing amount detecting unit detects the icing amount when the operation mode is the no-load operation mode.