Circuit breaker and transformer inspection and maintenance: probabilistic models

Circuit breakers and transformers are two of the most common components in the power system. Catastrophic failure of these components will result in high cost associated with the loss of load and component replacement. Preventive maintenance may reduce these costs by extending the components´ lifetime and increasing availability. However, too much maintenance may be costly while too little maintenance may result in catastrophic failure. Probabilistic models that will include the effects of maintenance on reliability are needed to perform cost benefit analysis and arrive at an optimal maintenance strategy. A probabilistic maintenance model introduced earlier for power transformer is proposed for circuit breaker uses in this paper. The model is based on data coming from a study of deterioration process, maintenance tasks, and inspection tests for circuit breakers.