Some Observations on the Dynamical Property of a Small Wind Turbine

We theoretically and experimentally studied on the dynamical property of a small wind turbine. We assumed that the aerodynamic properties of a blade were given by a torque coefficient, which was a function of a tip speed ratio only. A numerical model of a wind turbine having an optimum regulation system was given. We derived formulas of response time to the change of wind speed and load as a function of the torque coefficient, inertial moment and wind speed. We showed that the deviation of the tip speed ratio from the optimum value by the change of wind speed was approximated well to the second order of wind variation. The deviation was expressed by a function of characteristic frequency. We also got the expression for the phase difference between wind and power variations. Those results were in good agreement with the numerical simulation for the model. We propose a framework to discuss the dynamical property of a small wind turbine