A breaker-oriented fault analysis methodology

SUMMARY

This paper presents a methodology for fault analysis of multiphase systems with the following innovations: (i) a breaker-oriented modeling approach that enables the computation of fault currents through any circuit breaker in a system and (ii) the use of a three-phase model with explicit representation of neutrals, ground wires, and grounding systems. Explicit grounding models allow the simulation of faults to neutrals and to ground wires and help evaluate ground potential rise. The proposed breaker-oriented fault analysis is utilized in a Monte Carlo simulation to provide a statistical profile or distribution of fault currents through any circuit breaker. Such fault current profiles permit an evaluation of the risk of breaker failures caused by increased fault current levels that result from the expansion of power systems. The proposed fault analysis methodology is illustrated using a three-phase, breaker-oriented 24-substation test system. Copyright © 2012 John Wiley & Sons, Ltd.