A Mechanical DC Circuit Breaker with the Function of Suppressing Overvoltage

For the mechanical DC circuit breaker based on LC oscillation, the breaking overvoltage of the mechanical break is an important factor affecting the success of the breaking, and the excessively high breaking voltage may lead to the intermittent reignition and re-breakdown of the broken insulation during the recovery period. In this paper, a mechanical DC circuit breaker topology which can suppress the overvoltage of mechanical break is proposed. At the same time, the setting method of the key parameters of the voltage limiting branch and the transfer branch is studied, so that the voltage at the mechanical fracture in the process of breaker breaking is at a lower level. Finally, the adaptability of the topology to different short-circuit currents is verified, and it is found that the topology has good adaptability to the full-current breaking condition.