ABSTRACT
In normal operating conditions, a circuit breaker is in the closed position, and some current is usually flowing through the closed contacts. The circuit breaker opens its contacts when a tripping signal is sent to it. The puffer-type arrangement is most widely used in practical circuit breakers, and the gas usually flows in parallel to the arc axis in such an arrangement. The small diameter of the arc space and the relatively quiet transfer of energy along the radius justify application of the one-dimensional model for the calculation of energy balance in the high-current period. The physical arc model has always been used for improving understanding of the general characteristics of electric arcs. There are examples of successful application of the physical arc model to feasibility studies of circuit breakers in special circuitry. Evaluation of circuit-breaker performance is important for both completed circuit breakers and prototype circuit breakers.
