Patent ID: 7952214

Claim:
A wind power generation system in which a stator of a doubly-fed generator is connected to an electric power system, a rotor of the doubly-fed generator is connected to a power converter for alternating current excitation, the rotor is mechanically connected to a wind turbine, a direct current side of a power system side power converter connected to the stator and the electric power system is connected to a direct current side of the power converter for alternating current excitation, and the power converter for alternating current excitation excites the doubly-fed generator to allow the doubly-fed generator to supply generated power to the electric power system, said wind power generation system comprising: a control device for controlling the power converter for alternating current excitation and the system side power converter; a system fault detector for detecting a voltage drop of the electric power system, an overcurrent of a direct current component of the stator current, or an overcurrent of an alternating current of the stator current; a stator current detector for detecting a current passing through the stator; and converter operation means for allowing the power converter for alternating current excitation to start excitation of the doubly-fed generator after the system fault detector detects a system fault and the current of the stator is lower than a predetermined value.