Frequency Control Strategy Of The Wind Farm Based On VSC-HVDC

As a elean renewable energ,wind power generation draws more and more attion around the world. The double-fed induction generator prevails in the wind industry and VSC-HVDC is becoming one of the significant ways integrating wind farm into the grid.The system frequency issues about wind farm based on VSC-HVDC are investigated in this paper.The main achievements include:(1)Studied The mathematic model of DFIG.Derived the mathematic model of DFIG under stationary-phase and phase-rotating coordinates. Then analysis of the control strategy of DFIG. using the stator voltage orientation to achieve the decoupling control of active and reactive power.Finally,in the MATLAB/simlink enviroment established the mathematical model of the DFIG.(2) Derived the mathematic model of VSC-HVDC under phase-roataing connecting wind farm.Then,proprsed the control strategy of VSC-HVDC connecting wing farm.The side of wind farm use the fixed ACvoltage control to maintain the wind farm voltage stability.The side of network used the fixed DCvoltage control to main DC voltage stability and control the power exchange of VSC and grid. Finally,in the MATLAB/simlink enviroment established the mathematical model of the VSC-HVDC,verified the correctness of th control strategy.(3) Analysising the system frequency response characteristcs of the synchronous generator and the doubly-fed indution generator,while the frequency changes by the penertration of wind power. Then, the"virtual inertia"control strategy are proposed in the paper,which can provides dynamically frwquency support. Finally,in the MATLAB/simlink enviroment established the mathematical model of the system,verified the correctness of th control strategy...