AC circuit breakers are well-established technology today. However, DC circuit breakers are not that easy to design and build, since there are no zero crossings in a DC power supply. Mechanical switches and semiconductor switches are the two key elements used under various circuit topologies to design DC circuit breakers. However, mass-scale commercial DC circuit breakers are designed by modifying AC versions by connecting multiple poles or using permanent magnets inside the breaker due to the additional cost needed for the novel technologies except for special applications such as the aviation industry. Some of the major issues behind the DC circuit breaker design are fundamentally explained in this research with simple experimental results based on DC arc characteristics. And novel solutions were suggested based on the experimental viewpoint for both mechanical and solid-state versions of DCCBs in the full article. This digest version only includes an analysis of mechanical DCCBs.
