Research On Dual PWM Coverter Technology For The VSCF Doubly Fed Wind Power Generation System

With the increasing scarcity of the energy in the world, renewable energy has been attached great importance widely. As one kind of clean energy ,wind energy has great potential and has been developed rapidly. Wind power technology has become a research hotspot among scholars around the world. Focusing on variable speed constant frequency (VSCF) doubly fed wind power generation system dual PWM converter control technology ,the paper is written as follow.Firstly, basic principles of VSCF double-fed generator and dual PWM converter are studied, and Doubly Fed Induction Generator (DFIG) mathematical model basing on ABC three-phase stationary coordinate system is analyzed. Base on tne coordinate transformation principle, the DFIG mathematical model basing on d-q coordinate is derived, and the base topology and operating principle of dual PWM coveter is analyzed.it establish the theoretical foundation of creating the system simulation model.Moreover, according to the basic structure of PWM Grid Side Converter (GSC), a mathematical model has been established. The voltage oriented control scheme is utilized to meet the goal of GSC that it is controllable. And then the double close loop control provides the setting of PI controller utilizing the space vector pulse-width modulation. Finally, a demonstration of the control scheme has been shown by MATLAB/Simlink.In addition, a stator flux oriented control theory and DFIG mathematical model basing on d-q coordinate is employed to design the Rotor Side Converter control scheme. A discussion of double close loop adjustor contributes to both close and open loop of the PI setting using a u-w model stator flux monitor. Next, this process has been proved by MATLAB/Simlink.Lastly, based on the study of both GSC and RSC, both of two side is connected,the whole simulation of this system is built by MATLAB/Simlink. The results show the DFIG performs as the wind speed changing which is meet the requirement of GSC and RSC. Therefore, this is the condition of variable speed constant frequency and it proves the correctness of the system designed.