Sliding-mode control for grid-side converters of DFIG-based wind-power generation system

On the basis of the mathematical model of DFIG´s Grid-Side Converter(GSC) in two-phase stationary α-β reference frame, an improved control strategy of GSC is presented based on sliding-mode control (SMC). The method uses double-loop structure. Direct power control based on sliding-mode control is used in the inner-loop, and a sliding mode controller was designed to improve the dc-link voltage stability in the outer-loop. The controller has advantages of simple structure, high control precision, rapid response speed and strong robustness, which is designed with both the excellent transient and steady state behavior of the system in consideration. Simulation results confirm the reliability and validity of the control strategy.