Research On Voltage Control Of Wind Farm

Comparing with thermal power and nuclear energy, wind power is highly recognized on the society as a kind of natural resources which costs lower and has less pollution. Although wind power has the advantages of rich resources, high economic benefit and low pollution, it still has shortcomings which cannot be ignored:the fluctuations of wind resource. The uncontrollable speed and direction of wind, becomes the causes of instability wind power of the root causes of instability of wind power generation. The power flow calculation result will get fluctuant as the change of wind speed. Further more, when there is a fault happens in the grid, the wind turbine will absorb much reactive power from the grid, which will cause instability of power system.According to the problem of wind farm lack of voltage-reactive power adjustment ability, this paper has analyzed the principle of reactive power compensation technology and on-load transformer changer regulating voltage, then designed a reactive power and voltage coordination control strategy for the node voltage of wind farm accessing to the Grid, and optimized the control strategy according to the simulation. This paper has built the control strategy which is optimized in matlab/simulink software. According to monitoring the voltage and power factor of the accessing node, this paper well performed the control effect, and finally achieved the node voltage control effectively.The models of fixed speed induction generator wind farm and doubly-fed induction generator wind farm are built in the paper, and simulate in the following conditions: no control measures, just installing SVC and installing reactive power and voltage coordination control strategy. And at last the conclusions are given by the simulation results:(1) After installing SVC in fixed speed induction generator wind farm model, the adjustment ability of adjusting the voltage of PCC.(2) After taking reactive power and voltage coordination control strategy in fixed speed induction generator wind farm model, the adjustment ability of the voltage and power factor of the accessing node get much more better than that when only install SVC.(3) Reactive power and voltage coordination control strategy doesn’t have much effect on the node voltage control of the doubly-fed induction generator wind farm accessing to the grid.