Sensitivity Method On Voltage Stability And Its Applications In Guangxi Power Grid

Adopted sensitivity method,this paper studies and analyses voltage stability for Guangxi power grid(220kV and 500kV voltage level) in summer-heavy operation mode of 2006. Sensitivity method is a steady-state voltage stability analysis method based on power flow equation,and it analyses system stability by the system variable sensitivity index to the disturbance under conditions that the system is disturbed.It needs a few datas in sensitivity computing,and it is very simple during the computing process.The results can reflect much information.The physical meaning of various sensitivity indexes is relatively definite.while sensitivity indexs and margin indexs are used together to analyse system voltage stability,the conclusions are more general.Used BPA program,this paper does power flow computing for the basic datas of Guangxi main power grid. In addition ,various sensitivity indexes are calculated.As a result ,some datas are obtained,including bus sensitivity datas,line sensitivity datas,loss sensitivity datas, datas of P-V curve, datas of V-Q curve and N-1 outage simulation datas.According to these datas,some curves are ploted,such as P-V curves,V-Q curves,loss curves ,current changed curves,and so on.The sorting results of various sensitivity indexes and the changing tendence reflected from these curves are used together to analyse stability of Guangxi main power grid,and find out the weak buses,weak areas,critical lines and generators.Furthermore,some measures for improving system stability are proposed.These proposal can be taken as useful references to the grid construction for the future.In order to meet the need of dispatchers and administrators's understanding the real-time situations of the voltage stability of power grid , based on web, a voltage stability analysis software in power system is developed. The system structure is Brower/Server,and the web programming in the system is designed by Visual C#.NET, background database management system by SQL Server2000. During the development, the system security and the need for function extend are considered sufficiently.Finally,the system is able to release voltage stability datas on internet already.