Ac Excited Vscf Wind Power System

With the continuous enlargement in capacity of a wind-power generator, the efficiency improvement of electric power generation had been become more and more important .The Variable-Speed Constant-Frequency (VSCF) power generation, which is served to reach maximum wind-energy capturing and utilization for a variable blade-pitch wind-turbine, is the studying hot-spot of the wind-power generation technique at present. In the paper, the technical approach of vscf wind power generation using A.C excited doubly-fed induction generator was comprehensively investigated from theory to practice, from simulation to experiment.This paper firstly analyzed the performance characteristic and the operation principle of optimum utilization of wind-energy. The feasibility to imitate the maximum output power curve by using the DC motor has been testified by the simulation and experiment. The hardware structure of the imitation system is proposed and the effectiveness of the system has been proved by the laboratory experiments successfully. Secondly, to achieve the independent regulation of active and reactive power output from the generator side which is designed for the purpose of tracing the maximum wind-energy capturing .The paper has analyzed the mathematic model of the AC excited doubly-fed machine and the stator field orientation control strategy of the motor as vscf wind power generator. Thirdly, it has put forward and designed the dual PWM converter with the capacity of energy flowing bidirectional aimed at the demand of rotor energy bidirectional flow. The author constructed reliable and integrated experimental system and did a series of experimental study including no-load, cutting-in network and power generation at, below and above the synchronous speed. The result of the simulation and experiment all validated the validity and feasibility of theoretical model and control strategy.