Inspection schedule optimization technique for power distribution facilities

Power distribution companies must establish an optimal maintenance schedule that balances reliability and efficiency of a number of widely scattered facilities. Conventionally, Japanese power utilities divide their distribution areas into multiple inspection areas, and they maintain high reliability by periodically inspecting each area. A time-based maintenance scheme is generally inefficient. This paper proposes a method of optimizing inspection schedules of Japanese distribution facilities. A condition model is presented that predicts the next inspection timing of each facility using past inspection data. Moreover, an algorithm to minimize the inspection cost based on the predicted inspection timing is proposed. The algorithm can efficiently calculate the optimal combination of two inspection schemes, an area inspection scheme and an individual inspection scheme. Simulation results with test data show that the algorithm reduces the inspection cost by 15%. The proposed method results in a more effective inspection schedule.