A Novel Methodology to Incorporate Circuit Breaker Active Failure in Reliability Evaluation of Electrical Distribution Networks

The random failure of components in a distribution network leads to power supply interruptions to electricity customers. Among different failure modes in the distribution network components, active failure is more frequent and requires the circuit breaker operations to isolate faulty segments. Active failure of a breaker causes the operation of a backup breaker, thus, exposing the larger segment of the network to outages. This paper proposes a new analytical methodology to identify breaker active failure events involving different order of contingencies. This methodology introduces an active breaker incidence (ABI) matrix to capture the active failure of breakers leading to load point failures. The ABI matrix is concatenated to the incidence matrix of the minimal path to form a new incidence matrix which reflects the information of all failure events including active failure of circuit breakers. These failure events are then utilized to evaluate the reliability indices. The proposed methodology is illustrated in a test distribution network. A study conducted on the IEEE Gold Book Standard Network shows that that the methodology effectively identifies and includes breaker failure events to evaluate the reliability performance, and that the proposed methodology can be utilized to make investment decisions in modern industrial distribution systems.