A Bipolar Hybrid Circuit Breaker for Low-Voltage DC Circuits

Abstract

Presently available dc breakers fall into three categories, mechanical, static, and hybrid dc breakers. With the advent of dc generation, loads, and circuits dc breakers are required for system protection. This paper proposes an alternate method to break dc currents for low-voltage applications. Higher voltages have not been tested due to limited resources and safety concerns; however, the proposed mechanism can potentially be used at higher voltages. The proposed mechanism utilizes two switches along with two diodes, to reverse the direction of the current flow and clear the fault. This is different than the conventional single-switch commute-and-absorb method used in mechanical or static breakers in the sense that it reverses the current direction and delivers part of the fault energy back to the source. It is shown that the proposed method can break the fault current effectively with minimal arc and significantly reduces the voltage stress across the mechanical switches. The initial results of this work have been presented in the ECCE2021. Extended simulation and experimental results are provided to show the efficiency of the proposed dc breaker. In addition, the application of the proposed dc breaker is illustrated for dc distribution system via simulations and the design procedure is explained.