Modeling and Experimental Study on Grid-Connected Inverter for Direct Drive Wind Turbine

Abstract

This paper designs a dual topological structure of grid-connected inverter for high-power wind turbine, and introduces PWM converter's operational state. It establishes mathematical model of grid-side converter for wind turbine, then it puts forward the dual closed-loop vector control strategy of grid-side converter based on dq coordinate. The combination of the dual topological structure and decoupling control realize the functioning of high-power factor and two-way transmission of energy. Grid-side converter can stabilize DC side voltage during rapidly changed wind velocity which led to changes of output power in generator. Active or reactive output current can be adjusted independently. The hardware experiments and simulation results verify the feasibility of the proposed control scheme in both the high stability accuracy and excellent property of grid-connected.