Physical Simulation On The Control Of The Doubly Fed Induction Generator

As we all know, energy and environment are emergency problems which should be solved for human existence and development. Most of the energy source we consumed now are fuel and coal, which are limited and they also make serious air pollution. Wind power, as renewable and no pollution source, is paid great attention by more and more countries.This paper deals with physical simulation on the control of the doubly fed induction generator. The main contents of the thesis are as follows:Firstly, this dissertation analyzes DFIG's operation theory including mathematic model, coordinate transformation and power relationship, which established the theoretical foundation for succeeding study.Secondly, on the basis of the DFIG's model, this thesis discussed the power decoupling model, analysised its active power characteristics and reactive power characteristics, and then identified the reactive power limitation.Thirdly, a 4.8kw DFIG wind power system which consists of a induction motor,a set of linked dual back-to-back voltage-source converters and monitoring software,etc,is designed to analyse the influence of the wind power on grid voltage.The thesis constructs a laboratory distribution network for simulation experiment. Based on the system, an experimental research of DFIG output power decoupled control, maximum-power transfer and voltage -reactive power regulation was carried out. The experimental results testified the influence of the DFIG's reactive power on grid voltage.