Supercapacitor based approaches for arc energy absorption in direct current circuit breakers

AC circuit breakers are a mature technology, and are based on an arc chamber coupled with inductive arc absorption circuitry developed using commercial off the shelf components. In developing these, two zero crossings per AC cycle is effectively used, with capacitors, MOVs and other components used at the switch contacts to absorb the inductive energy in the AC circuit loop.Given that a DC circuit loop does not provide current zero crossings, arc extinguishing is not supported. Hence, commercial DC breakers are modified versions of AC breakers, usually the contacts of a 3 phase breaker poles connected in series to share the arc energy, sometimes combined with other transient absorbing components.This paper presents a preliminary results of a new approach for DC circuit breakers based on placing a supercapacitor based energy absorption loop, making use of the high current capability and the significant joule rating of a supercapacitor.

I. Introduction

Circuit breakers are a critical component of safety in both industrial and residential electrical circuits. Nowadays, the world is shifting away from environmentally unfriendly non-renewable energy sources toward renewable energy sources in response to global warming caused by damaging emissions from fossil-fuel combustion [1]. Consumer demand and government policies are bringing more efficient renewable energy technology to the world. As a result of spreading more renewable sources, direct current microgrids and also the dc loads [2] are gaining popularity throughout the world, as they remove alternate current to direct current conversion losses. Thus, with the proliferation of dc renewable energy sources and dc loads, reliable dc-circuit protection techniques such as direct current circuit breakers (DCCBs) are becoming paramount [3].