Simplified numerical modeling of rotational speed response for a small wind turbine

抄録

In this study, a simplified model equation is presented to analytically model the rotational speed of a rotor disk of a small wind turbine. Specifically, the response of the rotational speed to changes in the inflow wind speed is examined. First, the governing equations for the rotation speed of a small wind turbine are obtained in a dimensionless form using characteristic quantities. Therefore, the present analysis targets the non-dimensional inflow wind speed and rotation speed. Then, the profile of the tip speed ratio of the aerodynamic torque coefficient is used. Here, the profiles of aerodynamic torque coefficients for two small wind turbines are used. Using the first and second derivatives of the aerodynamic torque coefficient, the profile of the aerodynamic torque coefficient is described by a series expansion. Here, based on previous studies, it is not necessary to include the value of the second-order derivative. In view of the above, a simplified model equation using the aerodynamic torque coefficient and its first-order derivative is presented. The use of a reduced-order modeled accurate governing equation, such as that presented in this study, may provide a mathematical solution to describe the response of the rotational speed as a future study.