A model for optimizing maintenance policy for power equipment

• A new maintenance model for making optimal maintenance decisions.
• The model was developed as a function of maintenance interval.
• The model does not need of estimating parameters subjectively.
• The model demonstrates its applicability and simplicity.

Electrical utilities have the problem of applying complex mathematical models for maintenance optimization of power equipment. This is because the models presented in the literature lack the simplicity desired to carry out evaluations, and some others require a great number of input data, which may not be easily available. In order to overcome these difficulties, a new analytical optimization method for preventive maintenance (PM) policy with minimal repair at failure, periodic overhaul, and replacement is proposed for power equipment with historical failure time data influenced by a current PM policy. The method includes a new imperfect PM model based on Weibull distribution and incorporates the current overhaul interval T0T0 and the optimal overhaul interval T to be found. The Weibull parameters are estimated using a new analytical method. Based on this model, the optimal number of overhauls and the optimal overhaul interval for minimizing the expected total maintenance cost are also analytically determined. Several study cases were designed in order to test the proposed model, demonstrating its applicability and simplicity to determine an optimal maintenance policy.