Researching On Some Problems Of Underground Substation Designing In Great City

With the development of megapolis economy,especially the exploitation of the real estate,the service loads increase sharply.The distributing of transformer substations becomes more denser,and goes deep into intown shopping center,finance center and uptown center. So transformer substations are built in great city in face of many new prolems:the difficult substation site selection,the electromagnetic wave and noises'influence on environment,the harmony with surrounding buildings. The construction of underground substations is able to resolve those difficult prolems,thus they have great development potential.This paper puts forwards viable schemes through studied on substation location selection,main electrical connection selection,electrical equipments selection. (1)Contraposing the problem of substation location selection,I suggest to adhibit two-phase optimization planning:first it carries on the optimization planning using the computer program,we can achieve the most economic solution as the initial solution for the further planning; second the experts give synthesized grades of candidate solutions;finally make certain the optimization planning of for building sub station. (2) Contraposing the problem of main electrical connection selection,I suggest to adhibit four state models of components and assessed reliability and economic indices of bus configurations using minimal cut setmethod.(3) Contraposing the problem of electrical equipments selection, I suggest to adhibit LCC cost estimation, the life cycle cost is divided and estimated that find the balance between cost and reliability,so achieve the best economical decision and reduce the investment Of underground substation.Finally this paper enumerates also three representational and different voltage grades underground substations:the 110kV Zizhong Underground Substation,the 220kV Underground People's Square Substation, the 500kV Underground World Exposition Substation.