Cascading Reliability Model for HV Circuit-Breakers

Maintenance of power systems and apparatus is among the most discussed issues at the moment, since utilities require to reduce costs to make their companies competitive. It is obvious that reducing maintenance costs while keeping the high system reliability is not an easy task. In order to redesign the maintenance programs, the failure database and maintenance information must be provided. High voltage (HV) circuit-breakers are one of the most important equipment in power systems. They are subject to many abnormal conditions such as major and minor failures during the lifetimes. In order to study reliability and availability of HV circuit-breakers, these failures have been recorded in terms of database. In this study, the failure database of different types of HV circuit-breakers from 1960s is applied in order to investigate reliability of HV circuit-breakers. The durations between failures were investigated to establish the trend of failure development. Afterwards, cascading reliability model is developed. Finally, the exponential reliability distribution is implemented to simulate the failure development and to study reliability of HV circuit-breakers.