Research On Gird-side Converter Of Doubly-fed Wind Power Generation System

With the development of the renewable resource, the research of variousrenewable energy technology has been paid more and more attention. Windenergy has been paid close attention by many countries in the world, so theresearch and application of the wind power technology make a spurt of progressin the past few years.This paper mainly studies the grid side converter of the VSCF doubly fedwind power generator, the three-phase voltage source PWM converter topologystructure was selected, the work mainly including: the development presentsituation and the future prospects of the international and domestic field of windpower generation are outlined, the system structure of the wind power, controlstrategy, and the grid technology and the impact of the electric power systemwere simply introduced. From the introduction of wind turbine aerodynamiccharacteristics of generator, grid-connection control strategy was studied, thetraditional PI controller design based on fuzzy controller was designed, in orderto improve the robustness of the control system and dynamic properties, usingthe Simulink to build the model of the control system, the simulationexperiments are carried out. Focus on the principle of the grid side inverter,coordinate transformation, vector control method. The three-phase PWMinverter and a two-phase synchronous rotating coordinate mathematical modelwere deduced. At the same time the PWM inverter vector control strategy wasanalyzed. The control strategy of the grid side inverter of the wind power wasstudied, hysteresis current control was introduced, the repetitive control theoryto the design of grid side converter, and with that of a traditional voltage andcurrent double closed-loop control strategy were compared, the repetitivecontrol method for harmonic suppression characteristics were studied. Finallythrough the Matlab-Simulink simulation software to build a network sideconverter of repetitive controller simulation model, simulation results show thatthe repetitive control strategy for suppressing periodic harmonic influence the correctness and feasibility of the. Combined with the features of the TI’’sTMS320F2812DSP which is fit for PWM control, the hardware circuit wasdesigned. The main circuit, components selection and the peripheral circuit ofthe main controller chip were designed. According to the functionalrequirements of the control system, control software program of the inverterwas designed, which divided into the main program and interrupt program twoparts, including the signal input and output function and protection program.