Maximum Power Point Tracking of a Wind Power system based on The PMSG using Sliding Mode Direct Torque Control

Abstract

This paper investigates the novel Variable Structure Direct Torque Control (VS-DTC) scheme for Wind Energy Conversion System (WECS) based on the Permanent Magnet Synchronous Generator (PMSG) to maximize the generated power from wind turbine. The system includes a wind turbine, a PMSG, two converters and an intermediate DC link capacitor. The efficiency of the WECS can be greatly improved using an appropriate control strategy. Furthermore, the system has strong nonlinear multivariable with many uncertain factors and disturbances. Accordingly, the control strategy combines the technique of Direct Torque Control (DTC) and Sliding Mode (SM) nonlinear control theory. Considering the variation of wind speed, the grid-side converter injects the generated power into the AC network, regulates DC-link voltage and it's used to achieve unity power factor, whereas the PMSG side converter is used to achieve Maximum Power Point Tracking (MPPT). Simulation results, by Matlab/Simulink, have shown the effectiveness of the proposed control strategy for WECS based on the PMSG.