Circuit breaker condition assessment through a fuzzy-probabilistic analysis of actuating coil's current

摘要

Circuit breaker (CB) is a component providing significant electrical protection for power transmission and distribution systems. Hence, an effective condition monitoring system for the CBs is of imminent importance. This study presents a fuzzy-probabilistic-based condition assessment algorithm to assess the CB operation performance by monitoring its trip/close coil current (C.C.), and suggests a simple yet effective condition assessment tool. The C.C. patterns are acquired by measurements carried out on 60 CBs (72.5 kV, SF) under faulty and normal conditions. To intelligently assess the CB's operating state (i.e. normal, alarm and emergency), in terms of its reliability, the optimum C.C. features with minimum interdependence were obtained. Furthermore, a fuzzy-probabilistic method is proposed based on the results of the statistical analyses of the features. The feasibility and applicability of the proposed method in CB condition assessment is verified against the experimental measured data.