Mathematical model and procedure for arc-back current calculations for power rectifiers

THE anode and cathode circuit breaker fault currents experienced by mercury-arc rectifier equipment when an arc back occurs have generally been estimated by superposition of the results of greatly simplified calculations of individual a-c and d-c transient states. Such calculations have the merit of being easy and rapid to make. In some instances however the large differences between such estimates and actual tests have indicated a need for a more precise method of predicting the arc-back currents in rectifier circuits. This need has been particularly pressing in the case of circuits having large connected capacity, for as systems get larger the accurate prediction of the magnitude of arc-back currents to be handled becomes increasingly important in the design and selection of components.