The Grid Connection Control Research Of Doubly Fed Wind Power Generation System

The21st century has witnessed the rapid development of world economy, general energy crisis and growing environmental problems. It has been the mutual choice of the whole world to develop new energy and take the road of sustainable development. Power generation from new energy is the best way to use new energy resources. As its advantages of pollution-free, endless supply and easy accessibility, wind power generation system ends up to be the first choice of new energy development.This paper uses the various speed constant frequency (VSCF) doubly fed inductive generator (DFIG) wind power generation system as the object of study, gives detailed analysis on the control of the PWM converter and grid connection based on voltage oriented vector control strategy. The simulation and experiment results are also listed.Firstly, this paper introduces the system composition and its operating principle. Then the mathematical models of key components in2-phase synchronous rotating coordinate are built using the coordinate transformation theory based on the models in3-phase static coordinate. As to the dual PWM converter in the rotor-side circuit, space vector pulse width modulation (SVPWM) is introduced. The grid-side PWM converter can stably control the DC bus voltage and achieve unity power factor operation based on the grid voltage vector orientation control method. The rotor-side PWM converter can achieve effective grid control and power decoupling control based on the stator voltage vector orientation control method. Then simulation models are built based on the theoretical conclusion above using MATLAB/Simulink, which verifies that the simulation results and the control strategy are right and feasible.Secondly, the system software control concept and process are discussed. And the program design of several important parts of the system are analyzed in detail based on the chip of TMS320F2812DSP.Lastly, system operating experiments are done on the hardware platform, including no load operation, grid connection control and power control after grid connection. And the parameters and waveforms of the system running in lab condition are listed.