Research On Doubly-Fed Induction Generator Vector Control System

With the increasingly serious problems of energy shortage and environment pollution,domestic and foreign relevant person are actively researching and promoting the newenergy project. Wind energy as one kind of green clean energy plays an important role indealing with the human energy crisis and worsening environment problems. Research onwind power generation technology has become one of the main research fields at home andaboard.DFIG (doubly-fed induction generator) is an important part of wind turbine generatorsystem, in order to design an excellent wind generation system, determining its best controlmethod is primary. Based on the vector control technology, this paper takes wind turbinegeneration system consisted of DFIG and AC-DC-AC double PWM converter as theresearch object, analyzes its theory and simulates the system. Specific work mainlyincludes following aspects:1.Build the complete dynamic mathematical model of DFIG to lay the foundation fortheory of vector control strategy, analyze topological structure and working principle ofDFIG in detail. The system is divided into two parts, including vector control of rotor-sideconverter and vector control of grid-side converter.2.For rotor-side converter, in order to realize the flexible grid-connected of windgeneration system and apply the maximum wind tracking control after grid-connected,design the no-load grid-connected vector control strategy based on stator flux orientationbefore grid-connected. Program S-Function of DFIG in MATLAB, simulate no-loadoperation model and generation model. The simulation results indicate that rotor-sideconverter can track grid voltage exactly before grid-connected and realize variable speedconstant frequency and maximum wind energy capture after grid-connected.3.For grid-side converter, in order to control power factor of AC-side and voltagestability of DC-side, design the vector control strategy for grid-side converter based on gridvoltage orientation. Deduce calculation formula and setting method of PI regulator parameters in detail. Verify the correctness of control strategy and theory by simulation.4.Take TMS320F2812DSP as the core and use intelligent power modules and otherdevices to design experiment circuit, the design scheme and selection of hardware areanalyzed.