Breaking Performance of a Novel DC Contactor Concept

There is a general high market demand for novel switching devices in direct current applications. In this study a technology demonstrator for a low voltage DC contactor was made and evaluated experimentally. The overall concept is based on a double contact system where a fast moving arcing contact opens in slit-type splitter plates deep within the arc chute while the main contact opens with less velocity. To determine the DC breaking performance, only the arcing contact performance was investigated in this initial study. The results of the experiments showed that at lower currents the arc is extinct within the slit, with the arc being efficiently cooled by the narrow environment. At medium current level, the arc starts to activate the splitter plates and at even higher current, above 100 A, the arc efficiently moves in between the splitter plates. Generally, current levels between 5 to 750 A were successfully interrupted within 25 ms and stable arc voltage was achieved in the complete range The main conclusion from the study is that the demonstrated concept is a viable solution for an efficient low voltage DC contactor.