During the operation of traditional mechanical switches, there are the following transient processes: in addition to the arcing stage, which will burn the contacts and reduce the service life of the switch, the arc gap in the post arc stage is prone to reignition under the competition between the dielectric recovery (DR) process and transient recovery voltage (TRV), reducing the success rate of fault breaking. The common contact bounce and pre breakdown during the closing process may generate inrush currents and transient overvoltages, which also pose a threat to the safety of the power system.

On the other hand, with the development of power electronic devices, technologies such as thyristor switching capacitor banks, modular multi-level converters, flexible multi-state switches, and zero switching have shown good development momentum in the field of power systems. However, the problems of on state loss and low unit operating voltage in power electronic devices hinder their application and promotion in the field of power systems. In order to combine the advantages of the two types of switches and complement each other, researchers have proposed a new approach for electromechanical hybrid circuit breakers.

However, most of the hybrid switches used in AC application scenarios are simple mechanical fractures, with limited electrical performance parameters. They are mostly used in low load transformer on-load tap changers and distribution network reactive power compensation capacitor switching switches with a small proportion. Their control current and field stress are relatively small, making them unable to be applied in the field of large-scale distribution circuit breakers and large capacity reactive power compensation for medium and high voltage transmission lines.

The new electromechanical hybrid circuit breaker combines the advantages of mechanical switches and power electronic devices, overcoming the shortcomings of both. In order to reduce the impact of transient processes such as contact erosion, competition between transient recovery voltage and dielectric recovery process, and inrush current during the operation process of traditional mechanical circuit breakers, Guo Xingyu, Huang Zhizhi, Liang Deshi, and Zou Jiyan from Dalian University of Technology proposed a new topology structure for electromechanical hybrid circuit breakers used in distribution networks in the 24th issue of the Journal of Electrical Engineering in 2022, Realize non transient opening and closing operation within the range of medium voltage circuit breakers. The experimental results show that the zerozone process of the new electromechanical hybrid circuit breaker is dominated by parallel diodes, and the vacuum arc extinguishing chamber can achieve micro arc or even non arc breaking, eliminating the burden of vacuum switch arc extinguishing.