Health Index Determination of Aged High Voltage Substation in Distribution System

This paper presents condition assessment of high voltage equipment and substation as health index. Major equipment of high voltage substation consists of circuit breaker, disconnecting switch, current transformer, voltage transformer and surge arrester. The condition of equipment is assessed by visual inspection and electrical test. The weighting and scoring method is applied throughout the process of health index calculation. The Analytic Hierarchy Process is used to calculate the weight for each criterion. The conditional score and its weight of each testing are used to calculate the weighting average score. Then, the obtained weighting average score is adjusted by visual inspection, maintenance completeness and failure rate of equipment. The adjusted average score of all equipment in a bay is integrated into bay health index and subsequently adjusted by age and operational stress of bay. Finally, the health index of fifteen substations can be determined.