Optimization Method for Inspection Scheduling of 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. Such a time-based maintenance scheme is generally inefficient. This paper proposes a method for optimizing inspection schedules of Japanese distribution facilities. An inspection interval model is presented that estimates the inspection interval for each facility by using past inspection data. Moreover, an algorithm to minimize the inspection cost based on an estimated interval is proposed. The algorithm can effectively determine the optimal combination of two inspection schemes, an area inspection, and an individual inspection. Evaluations of results with test data show that the algorithm reduces the inspection cost by at least 14%, retaining system reliability. The proposed method results in a more effective inspection schedule.