One novel Variable-speed wind energy system based on PMSG and super sparse matrix converter

Aim to reduce the cost of wind energy conversion system and improve its performance, a novel variable-speed wind energy generation scheme which is based on the combination of PMSG and super sparse matrix converter (SSMC) is presented in this paper. The whole physical system including SSMC is modeled. Coordinate transformation, active power conservation principle and singular perturbation theory are applied to simplify the control law for SSMC. To design a global stable and robust controller, feedback linearization theory and H-infinity control are used. The stability of zero dynamics of the system is analyzed in detail. Based on the analysis of operation condition of SSMC, the limitations (reactive capability at both sides of SSMC) of the system are presented. It will be helpful to design the out-loop control strategy such as reactive power optimization control, maximum torque control of PMSG. The proposed generation system is not only able to realize maximum power tracking, but also reduce torque pulsation due to the distorted stator current in PMSM. At last, simulation results verify the feasibility of the proposed method.