Novel sliding mode controller for power control of a doubly fed induction generator in variable speed wind turbine

In this study, two sliding mode controllers (SMCs) are proposed for active power control and maximum power point tracking (MPPT) of a doubly fed induction generator (DFIG) in a variable speed wind turbine. The parametric indeterminacy and uncertainty results in inaccurate performance of the DFIG-wind turbine system and may lead to instability. The proposed SMCs can properly overcome the problems caused by parametric indeterminacy and rejects the disturbances. A new proportional-integral-type SMC (PI-SMC) is proposed by using control Lyapunov function method, also a new second-order SMC (SO-SMC) is designed by using the super-twisting algorithm. The proposed PI-SMC and SO-SMC are applied to the rotor side convertor (RSC) of DFIG in order to reduce the negative impact of chattering phenomena and increase the tracking accuracy. The simulation results of the proposed methods and vector control optimized by dragonfly algorithm, are compared, Wich results prove that using the SMCs leads to lower ripple and higher accuracy.