Closed Loop Stability of Switching Controller for Wind Turbine

Wind power intermittency due to wind speed variations can be alleviated by using a rechargeable battery as the reserve power source. In such an integrated wind turbine-battery system, wind turbine controller is frequently required to switch between two control modes. We have derived linearized approximations of the closed loop wind turbine system for both control modes after applying feedback control laws. Stability of this linearized switching system is established with the use of Common Quadratic Lyapunov Function (CQLF). Limitations on control gains and switching conditions required to achieve system stability are discussed. Simulations confirming the system stability are also presented.