Study. Liangang Grid Security And Stability

At present,many of the lardge or medium iron and steel enterprises put up a lot of generators by use of blast frunace gas,coke oven gas and redunt steam for saving resource and gaining more benefits.The generators distribute everywhere in factory.Restricted by former distributed network and economic profits,almost every generator synchronizes at the medium voltage level(10KV or 35KV).It enlarges the scale of distribution network and complicates the electric power network composition when building so many generator sets.This paper introduces the power system drawing of Lianyuan Iron and Steel group company,validates the enlargement of the short circuit current capabilit after distributed generators synchronizing by use of Power System Analysis Synthetical Programe.It suggests adding reactor accompanied with quick switch.In the one hand,the reactor reduces the short circuit current,on the other hand,it does not increase energy loss on the reactor.It analyzes the influence of distribution network protection system by distributed generation.In this foundation,this paper points out that it must modify the definite value of relay protection and optimize distribution network.Meanwhile it discusses detailedly the operation of ZCH and BZT when new grid facing system failure.This paper erects the mathematical model of Lianyuan Iron and Steel group company power grid,studies the transient stability when enterprise power grid isolated the main power grid by using BPA.The work of studying provides theory foundation for power grid safety and stability operation and put forward reference for other homologous enterprise.The creativity in this thesis lies in applying excitation system modeling method used in area grid into enterprise grid's generators,obtaining precise parameters of excitation system,assuring correctness of the simulation.