Circuit breaker arc model computations for critical line length determination

One of the most severe faults for a circuit breaker to interrupt is the Short-Line Fault (SLF). In this paper, digital testing is applied to determine the critical line length, i.e, the short-line fault percentage that stresses the circuit breaker most, for three different circuit breakers. Three are models have been used for the calculations and three indicators have been applied to determine the stress on the breaker. From comprehensive computations it appears that an SLF percentage higher than 90% is the most severe for the circuit breakers to interrupt.