DESIGN ASPECTS OF ENV SUBSTATIONS

Abstract

EHV substations are a vital link in present power grid systems of India. Their proper design involves a knowledge of all components, equipment, their arrangements, layout as well as their costs and reliability. In order to be able to design substation with high reliability and minimum cost, three main criterias namely, technical, cost and reliability have been considered. Technically the substation should have proper layout of equipments, operational flexibility, protection arrangement, simplicity and minimum maintenance requirements. In the present work, cost and reliability criteria of substation design have been discussed in detail. The various possible bus-bar arrangements for a 400 KV substation have been studied from the cost and reliability point of view. A comparison of the cost criteria for various bus-bar arrangements has been made and discussed in light of such study in other countries. The substation reliability has been computed by tie-set and out-set method. A computer programme has also been developed for this study. The substation reliability values for different bus bar arrangements have been compared. The dependence of system reliability on different component failure rates has been discussed. Reliability comparison of two bus bar arrangement on different component failure rates has also been discussed. The comparison of cost and reliability values of ring bus, duplicate bus, sectionalised bus and single bus arrange-ment has been made.