Current commutation from a fast-response circuit breaker to shunting conductor

Reasons of failures of fast response circuit breakers (FRCB) at multistage commutation of current in the circuit with an inductive storage ring are considered, when the current commutation in the shunting conductor (SC) is not completed. The commutation mode has been determined by five dimensional parameters: commutation current, stray inductance of the circuit, rate of voltage growth across the FRCB, initial resistance of SC and characteristic power contribution. The existence of two critical current densities is stated: the first one is related to the rate of voltage growth on the FRCB and the second one is associated with the ultimate maximum voltage developed by FRCB. The obtained calculation estimations permit to determine the current density upper boundary in SC above which the commutation is impossible