Determination of the optimum routine maintenance intervals for protective systems

Reasonable preventive maintenance mechanism can effectively improve the reliability of protective systems. According to the research on the reliability and economic, this study advanced a quantitative evaluation reliability model of protective systems based on semi-Markov process, and defined the annual average economic losses of protective systems. Therefore, the optimum maintenance interval was derived by minimizing the annual average economic losses. Through sensitivity analysis, this paper discussed the effect of the failure rate of the protection and the corresponding component protected, and self-checking effective rate on the optimum maintenance interval. The theoretical foundation has been established to determine the optimum routine maintenance intervals for protective systems.