Abstract:
Electrical equipment, such as power transformer, circuit breaker, busbar, power line, etc., is the important component in power system. Most of them have been long used for many years. During the long use, they are gradually deteriorated day-by-day. The deterioration will impact on the reliability of the whole system. Especially, the deterioration of equipment in electrical substation is very significant because electrical substation is the junction point of generation, transmission and distribution systems. Thus, maintenance is needed to ensure that equipment in electrical substation can be longer available. However, the current maintenance schedule in practice has been determined by fixed schedule basis (time based maintenance) which may cause unnecessary cost and reliability reduction. From all the reasons, this thesis proposes the optimal maintenance schedule for electrical equipment in electrical substation by considering system reliability, using Genetic Algorithms (GA). The failure probability of equipment is modeled by Weibull distribution which brings about an increasing failure rate as time passes. Finally, the optimal maintenance schedule, which minimizes the maintenance cost under a required reliability condition, can be obtained. Moreover, the proposed maintenance schedule considers load growth, inflation and electrical substation expansion. The maintenance cost consists of preventive maintenance cost, corrective maintenance cost and outage cost.The test results, with the sample electrical substations, show that the proposed method can find the optimal maintenance schedule with the minimized cost, when comparing with a time based maintenance under a required reliability condition.