Maintenance Prioritization of Existing Transmission Lines Using Priority Risk Indices (PRI)

This paper introduces a new model and the associated computer program for the prioritization existing overhead transmission lines for maintenance or refurbishment. The model calculates the priority risk index (PRI), which is the product of failure probability, line condition function, and failure consequences function. The failure probability of a line is calculated using the maximum capacities of the line components and the actual weather data from the nearest weather station. The line condition is a fuzzy function obtained using visual inspection and maintenance history of the line. The failure consequences are a complex fuzzy function of many parameters such as public safety, load supplied, impact on customers and system etc. This model would allow asset managers to optimize the use of available resources to achieve the maximum overall return on investment by allocating funds for the lines with highest priority risk indexes (PRI). Illustrative example is presented