Combining reliability attributes to maintenance policies to improve high-voltage oil circuit breaker performances in the case of competing risks

Abstract

This article deals with reliability attributes combined with preventive maintenance actions to improve the performances of a high-voltage oil circuit breaker. These attributes are examined using technical and organizational measures on the downstream feeder and the aim is to reduce the number of switching off due to failures; however, the maintenance actions are operated on the high-voltage oil circuit breaker to reduce the degradation velocity. The competing risks are highlighted by degradation process effects due to the continuous use of the device and by the shock process due to solicitations when a short-circuit occurs in the downstream feeder. From theoretical point of view, this article shows the modelling process to express the state probabilities and the dynamic reliability changing. From the practical point of view, it shows the ability to implement under MATLAB software package the theoretical models constructed firmly. The obtained results show that the effects of shocks are more significant than those due to degradation process and the high-voltage oil circuit breaker performances are more affected by the downstream reliability changing than by the preventive maintenance actions. Finally, this work has highlighted a global way to investigate protection device performances and has shown the attributes of reliability not only to ensure a high quality of service to power customer but also how to preserve the integrity of a critical device in the power system.