| Due to the characteristics of fluctuation,randomness and intermittence of wind power generation,low utilization hours,poor power quality,difficult peak load regulation and voltage regulation pressure of power grid.It has a great impact on the safe and reliable operation of power grid.How to eliminate or reduce the negative impact of wind power generation on power grid operation and reasonably connect wind farms into power grid Power network has become the main factor that restricts wind power generation.Therefore,this thesis makes a detailed study and analysis of the impact of wind farm access on the operation of the grid system and the optimization of the scheme.This thesis analyzes the economic situation and the increasing trend of load and electricity in DeQing,ZhaoQing,and forecasts and analyzes the power load of the power grid.Combining with the structure of DeQing power grid and power development planning,the wind power acceptance capacity of DeQing power grid is studied and analyzed in detail.Two feasible access schemes for DaDingShan wind farm are proposed.The optimal access schemes are analyzed and compared in terms of economy,voltage level and operation mode.The validity and feasibility of the schemes are verified.The power system simulation software PSCAD is applied to simulate the operation of DaDingShan wind farm after it is connected to the system,and the system configuration and operation suggestions are obtained.The configuration of relay protection and reclosing mode of wind power supply access system is analyzed.The configuration of reactive power compensation equipment and capacity at grid-connected point is analyzed because 110 kV GuanXu station is not put into operation.The voltage and loss of the regional power grid under the normal operation mode after the wind farm is connected and the important line faults are analyzed respectively from the summer and winter modes.At the same time,the worst reactive power regulation scheme of AVC is compared with that of manual intervention,and the optimal reactive power regulation scheme is obtained.After comparing the theoretical research and practical application of various measures,the following conclusions can be drawn:DaDingShan wind farm in DeQing of ZhaoQing is connected to the system through 110 kV GuanXu station.In order to improve the reliability of operation,it is suggested that the relay protection should consider the protection action of the 110 kV KangGuan line on the side of GuanXu Station,instead of jumping off the local switch,it should jump off the 110 kV DaGuan line to make GuanXu Station and XiangShan Station lose voltage quickly,and restore power supply through the Check no-voltage reclosure of the side inspection of KangZhou Station.After calculation and simulation,the reactive power compensation capacity of GuanXu station should be 4.008×4 MVar.Under normal operation mode,the optimal reactive power regulation scheme under manual intervention can ensure that the voltage of each voltage detection point is qualified,the network loss can be reduced by 1913,000 kWh in summer mode and 622,000 kWh in winter mode.For permanent faults of 110 kV DaGuan Line,the optimal reactive power regulation scheme under manual intervention can reduce power loss by 250 kW in summer mode and 50 kW in winter mode.For instantaneous faults of 110 kV KangGuan Line,the optimal reactive power regulation scheme under manual intervention can reduce power loss by 670 kW in summer mode and 260 kW in winter mode. |
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