Study On The Technology Of Variable-Speed Constant-Frequency Doubly-Fed Wind Power Generation

With the growing rating of the wind energy generation system, improving the operation efficiency of machine group is becoming important study work of wind power generation technology. The Variable-Speed Constant-Frequency(VSCF) wind power generation system with Doubly-Fed Induction Generator(DFIG) that can capture the maximum wind energy is becoming the hot point of study. This paper first has analyzed the performance characteristics of the wind turbine and the operation principle of the maximum wind energy capture. This laid a foundation for the study of control strategy of DFIG. Next, this paper has analyzed structure characteristics,opration principle and energy relationship of DFIG,deduced and built mathematic models of it on the three phase stationary and two phase rotating coordinate systems, put forward the stator flux oriented vector control strategy of DFIG for the realization of maximum wind energy capture and decoupling control of active and reactive power.Then, this paper has studied the back-to-back PWM converter that satisfies the request of energy bidirectional flowing of DFIG's rotor and its control strategy. Finally, this paper has built the simulation model of the Variable-Speed Constant-Frequency Doubly-Fed Wind Power Generation system, validated the validity and feasibility of theory, model and control strategy through simulation.