Research On Safety And Stability Of Yongji Power Distribution Network

Since the electricity was discovered,the scale of national power grids continues to increase.Many countries suffer from voltage collapse due to insufficient grid stability.Voltage collapse will influence people's lives.The safety and stability of the power grid are gradually valued by power practitioners.China's power industry is gradually development from small power grid to large power grid.But the power grid more huge,he security and stability of the power grid are more important.Distribution network directly affects user power quality.So it makes sense to ensure the safety and stability of the distribution network.Yongji is in the south of Shanxi Province.It's power grid is a typical receiving distribution network.With economy development rapidly in recent years.Some substations have occur aging equipment,insufficient margin,tight power during high load period,heavy load transmission lines,etc.,It will affect people uses electricity.So it is very important to study the safety and stability of Yongji power grid.This article first uses the PSASP(Power System Analysis Software Package)to build its simulation model based on the specific situation of Yongji Power Grid.Carry out the simulation of the power flow under heavy load in winter and summer.Calculate and compare the phase angle of each node voltage.Judge the weak point and Study grid operation under maximum load.Based on calculation results,make failure safety analysis,line current carrying capacity calculation and transformer load ratio analysis.Comprehensive judgment based on transformer load ratio and overall grid load ratio.Then determine the best load ratio of Yongji power grid.Suggestions for improvement on outstanding issues.Resolving measures for individual line overloading.Replace the Renwang line model for LGJ-240.It not only solves the current line overload problem,but also meets the load growth demand within 5 years.According to the load growth of Yongji power grid,useing the modal method to make the static voltage stability analysis.Find the initial participation factor and the limit participation factor of each bus bar.Calculate the comprehensive participation factors of each node,and compare them to find nodes and regions with high participation factors and weak node.Thencalculate the P-V curve of each node of the system.Using the regional load margin method to discriminate and analyze the load active margin of each node.On the basis of the results of each analysis and discuss the solutions.Take a variety of improvement measures for the case where the weak point voltage is low.Including regulating transformer taps and add SVG.Finally,propose many solutions aim at the problem of power shortage in Yongji power grid.That can effectively reduce the voltage force when the load peaks.According to various calculations and analysis,combined with the future planning and development of Yongji government.Proposed some problems that the grid may encounter in the next few years.Such as Dongcun change,the growth of agricultural load in Yuxiang is accelerating.The electricity consumption planning of the economic development zone has led to a sharp increase in the industrial load of Lidian.Make some suggestions for the current operation of the Yongji distribution network.It has certain significance for the future development of the power grid.