Research On Maximum Power Track Control And Modeling Of Double-fed Wind Turbine

Energy and environment has become a urgency problem of human survival and sustainable development. Because of pollution-free, shor construction for wind farm and its good social and economic benefits, wind turbine has began to receive attentions and has been actively developed. As the wind turbine started late in China, now the core of the control system and the main components are also dependent on impors, therefore in-depth study of wind turbine system simulation and control system has important theoretical significance and value in engineering.Though the analysis of the structure and composition of the doubly-fed wind turbine system, paper establishment a model of doubly-fed wind turbine system in PSCAD composed of model of wind, model of wind turbine, model of doubly-fed gererator, model of transfomer, model of converter and so on.By studying the working principle and characteristics of the doubly-fed wind turbine, the paper makes the theory research of the doubly-fed wind turbine, and gives the equialent circuit of the wind turbine doubly-fed wind generator. Then the mathmatical model of the wind turbine doubly-fed generator has been obtained by the coordinate transformaton.With the operating characteristics analysis of VSCF doubly-fed wind turbine, the doubly-fed wind turbine operating area is divided into three phases, and proposed control strategies for each stage, maximum power point tracking control for varivable-speed operation has been sdudied in this paper. This paper design the rotor-side converter controller and the network-side converter controller for back-to-back converter based on the maximum power tracking control strategy of variable-speed operation, and advanced SVPWM has been introduced in the controller design. And in this paper the implementation and simulation model has been introduced in PSCAD, and the simulation results prove the validity and advantage of the SVPWM.At last a complete wind turbine simulation platform has been implementated in PSCAD. This paper study the maximum power tracking control through the simulation of operation of DFIG, and the results prove that the controller of rotor-side and grid-side converter based on SVPWM can control the doubly-fed generator to track the opimal power factor and make the DC voltage to remain stable.