Research on Trigger Characteristics of Electrically Surface Flashover Triggered Vacuum Switch with Different Trigger Electrode Materials

The trigger characteristics of surface flashover triggered vacuum switch are affected by work function, ablation resistance and other parameters of the trigger electrode material have a great influence on the trigger characteristic parameters. This paper builds a test circuit based on a prototype of a surface flashover triggered vacuum switch. It compares the changes of the switch trigger delay with trigger voltage, working voltage and other factors under different trigger electrode materials, and analyzes the field emission characteristics of metallic and non-metallic materials. The experimental results show that compared with other metal materials, graphite material will obtain better switch trigger characteristics when used as a trigger electrode material. When near the critical breakdown voltage, the electrical surface flashover triggered vacuum switch has the problem of large time delay and delay range. As the trigger voltage increases to 120% of the critical breakdown voltage, the trigger delay and delay range are significantly reduced, becoming steady. Increasing the voltage of the main gap, the trigger delay shows a decreasing trend. Under the experimental conditions of maintaining the main circuit current of 1kA, the performance of the graphite trigger electrode is stable and the life performance is good after 200 experiments. Experiments show that graphite as a trigger electrode material has better performance and life performance than metal under current conditions, and is more suitable for applications with higher stability requirements.