Supercapacitor-based Pulse Energy Pumping Approach for Arc Extinguishing in Mechanical DC Circuit Breakers

DC circuit breakers (DCCB) could be developed based on three different concepts: (i) mechanical, (ii) solid-state, and (iii) hybrid. Commercialized DCCBs are adaptations of AC mechanical circuit breakers by placing multiple AC circuit breaker poles in series and/or using permanent magnets. Turn-off semiconductors are used in solid-state and hybrid DCCBs in the commutation path, and the residual energy associated with the parasitic inductance is absorbed using MOVs. Implementing a solid-state or hybrid DCCB is complicated and costly, and stretches available high voltage/current transistors/thyristors to their limits due to the immaturity of present semiconductor technology. This paper proposes a new approach designing a DCCB that makes use of the low-voltage and high-current delivery capability of supercapacitors. The lower voltage ratings of supercapacitors enable the use of low-voltage semiconductor switches, offering a significant advantage. The presented research extends the experience gained in developing different types of supercapacitor-assisted (SCA) techniques mainly a transient surge voltage absorber. An experimental verification of the proposed design is provided as a proof of concept for reducing the duration of electric arcs associated with 576 W, 2 kW, 4.2 kW, 8.5 kW, and 21 kW DC systems by 41%, 47%, 32%, 33%, and 10%, respectively, using the novel technique.