Patent ID: 8610298

Claim:
A method of operation of a wind turbine to guarantee primary or secondary regulation in an electric grid, applicable to a variable pitch and a variable speed wind turbine, comprising, controlling the network frequency by guaranteeing a specific percentage of active power reserve, the active power reserve being achieved by controlling, in a coordinated manner, speed regulation of the wind turbine by selectively performing one of: a) controlling an upper limit of a speed regulator that acts on the generated power of the wind turbine; b) controlling a lower limit of a speed regulator that acts on a pitch angle of the wind turbine, and; c) controlling both the upper limit of the speed regulator that acts on the generated power and the lower limit of the speed regulator that acts on the pitch angle; wherein, when controlling the upper limit of the speed regulator that acts on the generated power, the speed regulation comprises: calculation of a network frequency deviation with respect to a nominal value for the network frequency; calculation of the necessary active power reserve to compensate for the calculated frequency deviation; calculation of a maximum limit of power to be generated based on the calculated active power reserve and updating of the upper limit of the speed regulator that acts on the power generated; and operation of the wind turbine by applying the updated limits to the speed regulator that acts on the wind turbine output; and wherein, when controlling the lower limit of the speed regulator that acts on the pitch angle, the speed regulation comprises: calculation of the network frequency deviation with respect to the nominal value for the network frequency; calculation of the necessary active power reserve to compensate for the calculated frequency deviation; calculation of a minimum pitch angle based on the calculated active power reserve and updating of the lower limit of the speed regulator that acts on the pitch angle; and operation of the wind turbine by applying the updated limits to the speed regulator that acts on the pitch angle.