Modeling electrical arcs for power circuit-breakers

Measuring and predicting the interrupting limits of modern circuit breakers by means of modeling is discussed. The operation of SF/sub 6/-insulated breakers is described. Post-arc-current measurement and extraction are addressed. Once post-arc current and voltage recordings are available from a test, they may be used to analytically extract the two main parameters, arc time constant and nozzle cooling power. These can be used in the Mayr model to represent the dynamic arc resistance as a circuit component and will predict, by modeling, whether current interruption occurs or not for different testing stress levels or test circuit configurations.<>