Patent ID: 7966103

Claim:
A wind turbine for providing electrical power to a grid under low output voltage and variable power conditions, said wind turbine comprising an AC generator having a stator and a rotor with variable pitch blades operationally connected thereto, said wind turbine comprising; an output power sensor; an output current sensor; a first sample and hold for holding a first value established before the low output voltage condition; a second sample and hold for holding a second value established before the low output voltage condition; a rotor inverter controller comprising: a power to current converter for receiving the value from the first sample and hold and generating a current reference signal, an error detector for generating signals dependent on an error between the current reference signal and an output current signal from the current sensor, a PWM coupled to the error detector for generating rotor drive currents to establish stator output current values dependent on the reference current signal; and blade pitch controller for receiving the value from the second sample and hold and a signal from the output power sensor and adjusting the pitch of the variable pitch blades dependent upon the output power signal during low voltage condition and the value from the second sample and hold.