A Novel Fault Isolation Scheme in Power System with Dynamic Topology using Wide-area Information

Abstract

The flexible and dynamic operation condition of the power system requires that the fault isolation scheme has sufficient adaptability. A novel fault isolation scheme based on wide-area information is proposed in this paper. Based on graph theory, the adjacency matrices of the electrical components and circuit breakers are constructed. The real-time switch status data is exploited to reflect the dynamic changes of the network topology. Then, the tripping path of the circuit breaker connecting each protected electrical component is searched by the Floyd-Warshall algorithm to formulate the fault isolation set for all protected electrical components. The proposed approach is applied to fault isolation from a wide-area perspective, and it is not affected by system coordination and selectivity compared with the one based on local information. The effectiveness of the proposed scheme is verified on a power system with the typical electrical connection under the cases of a single fault, multiple faults, circuit breaker failure, and substation with the outage of DC power supply, and the case where the circuit breakers cannot trip. Since the tripping sequence of the circuit breakers is determined before the fault occurs, even with dynamic changes of the power system conditions, the proposed scheme can minimize the fault isolation zone with low fault clearance time.