Research Of Vector Control System For Doubly-fed Induction Generator

Reproductive energy can protect environment and promote the development of societyand economy,so it gradually takes place of no-reproductive energy.As one of the reproductiveenergy, because of technique enhancing, increscent capacity and price cutting down,windenergy becomes more and more popular than other reproduetive energy. It is a fact that the a.cexcited variable-speed constant-frequency(VSCF) wind generator system is becaming a mainsubject in the wind electric power generator field．It very fits for wind electric powergeneration with VSCF because it can capture as much energy as possible．An alternatingcurrent excited generator has many excellent characteristics, it may improving the stability ofelectric power system, its rotor speed may adjustable,it has abilities for realizingindependentregulation of active power and reactive power.In this paper, double-fed asynchronous generator is used to achieve variable-speedconstant-frequency. Firstly the paper introduces the fundamental principle of variable-speedconstant-frequency(VSCF) wind power generator, and deduces the mathematical model ofVSCF wind-power generator. By analyzing the grid-side converter and the rotor sideconverter of double-fed asynchronous generator, the control method and the idle loadgrid-connection of wind-power generator are introduced. Then the mathematical model withno-load and control method are also introduced.Secondly, the work principle and technical advantages of alternating current excitationwind power generator under VSCF condention are described. Then deduces the mathematicalmodel in A-B-C three-phase coordinate and d-q coordinate, and analyses the relation ofperformance characteristic, active power and reactive power.Thirdly,based on the analysis of the dynamic mathematieal model of DFIG and itsstator-flux-oriented vector control,a dual closed-loop PI control scheme is developed andrealizes decoupled control of the active and reaetive power. Simulation study is carried out onthe Platform of Matlab/Simulink and validates the proposed strategy. Finally,the paper made a part of the hardware,and debug the software of the controlsystem, the paper also gives the related experimental debugging results of the circuit.