Actuation of wind-loading torque on vertical axis turbines at model scale

A method for applying aerodynamic load to model-scale wind turbines is developed and implemented on the UC Berkeley Multiple Integrated Synchronized Turbines (MIST) model platform. A floating platform is subject to loads from incident waves and wind. These hydrodynamic and aerodynamic loads are unsteady. Though many wave (tow) tank facilities exist worldwide, only a select few have the capabilities to test model-scale winds and waves simultaneously. Thus, model testing of a floating platform with a wind turbine remains cumbersome and expensive. In this study, a Real-Time Hybrid Testing (RTHT) method is used to actuate the simulated aerodynamic forces on a model wind turbine. The actuator as developed can be mounted directly to the model turbine shaft and behaves as a stand-alone system that has its own processing capability for closed-loop control. This method is particularly useful for tests that allow platform motion. The selected hardware for the aerodynamic thrust actuator is a motor and a propeller. System design, hardware selection and integration, and an evaluation of the performance of the actuation system as conducted by (Koukina, 2014) are presented in this paper.