Emulation for torque-speed characteristics measurement of rotor blades in wind turbine using speed control approach

The technological development of wind turbines has attracted wide attention over past decades. Generally speaking, the power and torque characteristics of the rotor blades at different specific wind speeds determine the performance of a wind turbine. Furthermore, the wind turbine in the unstable state will keep accelerating until it attains stability or decelerating until it stops. Thus, blade characteristic can only be measured in a stable operating state. This paper presents a control scheme that enables the measurement of the blade characteristic both in stable and unstable operating states. In the proposed approach, a velocity controlled electric motor is connected with the wind turbine to regulate the rotational velocity of the rotor blades. The feasibility of the proposed scheme is evaluated numerically. The results show that the proposed scheme enables the regulation of the rotational velocity and realizes characteristic measurement even in an unstable operating state.