The Study Of Wind Power PWM Rectifier Based On Adaptive Sliding Mode Control

The wind energy has many advantages, for example: clean, highly efficient short workcycle and non-polluted, so it arrest the attention of the people all over the world. Wind powerindustry has been an unprecedented development with the development of wind powertechnology and the implementation of the policy encouragement. With the increasement ofwind power and network capacity, power system is affected more and more obviously. Soresearching converter and control strategy and the application of power electronic devices arethe two key factors to improving the wind quality. Deflector is the direct factor inconstraining wind power can grit or not, the rectifier is a device that can transform AC intoDC, which is an important part of the deflector. Now, there are many types of deflector, suchas: dual-PWM deflector, non-controlled rectifier+boost chopper+PWM inverter,non-controlled rectifier+Z-source inverter. But they are some disadvantages more or less,including high price, complex control and low power factor, which are very urgent problems.According to the principles and characteristics of the PWM rectifier, this article adopts thisprogram. Because of the uncertainty of the wind speed and robustness of adaptive slidingmode control, this article adopts adaptive sliding mode control.Firstly, this paper introduced foreign research of wind power and state of domestic andthe significance, emphatically Introduced the basic operating principles of direct drive windpower generation system，this dissertation established mathematical model and researchedcontrol strategy, specially double-loop control SVPWM control strategy. Generalmathematical model and mathematical model in d-q coordinate system were established.Simultaneously simulation of machine-side PWM rectifier proposed in this paper is made byusing Matlab/Simulink, and achieved a good simulation results.Secondly, this paper developed a LVRT based on adaptive sliding mode control, andachieved a good simulation results which demonstrated the system can capture the maximumwind energy and transmit energy, keep the frequency consistent with the electricity grid,achieve unity power factor in power transmission.Finally, hardware structure and some of the hardware circuit and software processes aredesigned based on VSC control system, hoping it will be helpful to the future research work. This paper designated the hardware circuit and software flow chart of the machine-side of thePWM rectifier based on direct drive wind power system.As a validation of the theoreticalanalysis and simulation, this paper researched machine-side of the PWM rectifier in the caseof normal and the case of low voltage based on2KW direct drive wind power system, theseexperiments proved the feasibility of the LVRT based on adaptive sliding mode control.