Prioritizing CBs Maintenance and Identifying Mandatory Maintenance at Higher Priorities

Abstract

Preventive maintenance (PM) based on condition monitoring of circuit breakers (CBs) provides proper and timely maintenance of CBs and reduces their failure rate as well as network costs. Condition monitoring of CB considers functional age (not natural age) of CB. This functional age depends on CB erosion. In this paper, CB condition assessment is obtained by monitoring the coil current and its duty cycles. Then, the maintenance priority between CBs of a power network is achieved using self-evaluation decision-making algorithm (SEDMA). This algorithm works in such a way that both the performance of CB is tracked by itself over time as well as compared to other CBs. First, this means the condition of the CB is measured by itself, and if the condition of the CB deteriorates over time, the CB will be given priority for repair. Second, the CB is compared offline with other CBs, and owing to the CB failures compared to other CBs, the priority of CB repair will be finalized. Then, using sensitivity analysis, it is determined whether the CB with the highest priority needs to be repaired or not, and the failure level of each CB will be specified. The case study in this paper concerns about two similar CBs. Also, the effect of improving the condition of the CB will be determined by performing maintenance operations. Eventually, it will be clear which CB has a higher priority for maintenance and whether this higher priority justifies the need for maintenance or not.