Optimization Of Reactive Compensation Capacitor Bank In Smart Electric Distribution Network

The three winding transformer substations of110kV generally add the parallel capacitors in10kV low voltage side to meet the power grid demand on reactive power. One of the two reasons is saving the cost of the reactive power compensation device, and the other is considering the35kV medium voltage side load reactive power should be compensated by the next level substation. As the load increasing, adding the parallel capacitors in10kV low voltage side can not meet the requirements of power factor in high voltage side of transformer.In this paper, researches on economic benefits after installing capacitor set in35kV side,and the optimal selection of allocation sites and number of reactive sources in the distribution network with DGs are made.Based on a research of capacitor set configuration in110kV substation, analyse the transformer loss and economic benefits after installing capacitor set in35kV side,and then put forward a110kV substation capacitor set optimization design that suitable for110kV substation.Use an intelligent optimization method to reduce the loss of the largest distribution network node corresponding to the optimal solution,find out the optimal selection of allocation sites and number of reactive sources. The test results for IEEE33system, although preliminary, have verified the feasibility and effieiency of the PSO based transmission network optimal planning method.