A robust continuous conduction mode control strategy of switched reluctance generator for wind power plant applications

Control of a switched reluctance machine (SRM) is relatively complex due to its highly nonlinear characteristics. The control parameters, such as turn-on angle, turn-off angle, and the reference current, have to be precisely changed with speed and the desired power or torque level to provide optimal performance. This paper presents an innovative, simple, and effective control strategy of SRM, operating in continuous-conduction mode (CCM), for a wind power plant application. First, the procedure for determination of the optimal control parameters as a function of rotor speed that provides maximal output power of SRM is described. Thereafter, the control angles versus speed dependences are linearized to be used for control of SRM in the wind turbine generator system (WTGS). Output power of WTGS is simply controlled by controlling the DC supply voltage of SRM. In the simulations performed to study the proposed control strategy, a realistic wind profile is used. Simulations results provided for the WTGS with and without pitch control confirm that the proposed control strategy ensures high efficiency of SRM, system stability, and fast maximal power point tracking under any operating conditions.