Matrix Converter In The Wind Power System Applications

Matrix converter is a new AC—AC converter, which has competitive advantages that bidirectional flowing of power can be true in four quadrant operation, without intermediate DC link, input/output current sinusoidal, input power factor could be controlled. So Matrix converter is a new direction of Power Electronics Technology.This article first briefly introduces the matrix converter about the basic circuit topology, the Synthesis of the bi-directional switch, current commutation and several current widely used modulation strategy. Then gives the actual matrix converter circuit and the matrix converter mathematics model has been set up in 3-phase static and circumrotate coordinate system. The analysis results on its switch matrix show that the amplitude, phase and frequency of output voltage and input fundamental displacement factor of the matrix converter is not only could be controlled freely, but also can be able to adjust input power factor and plays the role of SVC. Based on the mathematical model, this paper has established scalar quantity and double closed-loop control structure, and then simulation the double closed-loop control structure with fixed-band hysteresis current control strategy. Simulation results show that input signal and output signal are both sinusoidal, and they also indicate that the double closed—loop structure could reduce output harmonious waves, improve the current quality. Finally this article analyzed the mathematical model of wind turbine, compared to the current different types of variable speed constant frequency wind power systems. Based on doubly-fed generator's stator flux oriented dq coordinate system, the double-fed wind power generation system model is established. Then the article conducts a simulation analysis. The simulation results showed that the matrix converter in doubly fed induction generator system is feasible and effective.