A reliability centered optimal visual inspection model for distribution feeders

For an electric power distribution system, highly reliable operation is important for maintaining customer satisfaction. To maintain high levels of system reliability, inspection is used to identify potential problems, allowing necessary maintenance actions to be taken before failure occurs. The question is then how much inspection is required to maintain high reliability levels. This paper describes a Markov model of the inspection process. The model finds the optimal inspection frequency by considering the tradeoff between the cost of inspection and the cost of poor reliability. An objective function is formulated that minimizes the total cost of inspection, repair, and reliability. This model has been specifically created for determining the optimal visual inspection frequency for distribution feeder rights-of-way. The results from applying this model to a practical distribution system are presented, and extensions of this model to other systems are discussed.