Characteristics of Arc-Induction Type DC Circuit Breaker Depending on Alteration of Induction Needle

Abstract

The existing DC (direct current) circuit breakers used for LVDC (low-voltage direct current) extinguish the arc by using an arc chute. The arc chute has an insulating inner barrier and cuts off the current by increasing the length of the arc and raising the arc voltage. If the arc chute fails to extinguish the arc energy by dissipating heat, the arc generation time will increase, thereby raising the possibility of damage to the cut-off contacts. Therefore, we proposed a new arc-induction type DC circuit breaker with key components like mechanical contacts, an induction needle, and a magnet. The arc generated between the contacts is guided to the induction needle and then grounded via a ground wire before being extinguished. The induction needle is a critical component of such mechanism because it induces the arc. The performance of the DC circuit breaker is determined by modifying the induction needle. In this study, the operational characteristics of the arc-induction type DC circuit breaker according to the variation of the induction needle was analyzed using the Maxwell program. The shape and position of the induction needle were changed, and the changes in the electric field were compared via simulation. As a result, the electric field value was confirmed to have been improved by up to about 20.5% when the two variables were applied.