Abstract
We studied on output power of a wind turbine with fixed-pitch angle wings in variable-speed wind. A mathematical model of the wind turbine is given, and numerical simulation was done. In the model, we assumed that the torque coefficient was characterized by a tip speed ratio only. We showed thatthe displacement of the tip speed ratio from the optimum value, at which a wind turbine had maximum output power, due to aperiodic change of wind speed can be analyzed well by a characteristic frequency. The characteristic frequency is given by the inverse of the response time, which was derived in the former report. Output power of a wind turbine in variable-speed wind was given as a function of an averaged power coefficient and the variance of wind speed.
