Studying of the Operating Mechanism of the Triggering Circuit inside a Switching-type SPD

High sparkover voltages in the switching-type surge protection device (SPD) is one of the main problems to this type of SPD. In this paper, an active triggering circuit is designed to solve this problem by analyzing the operating mechanism of the switching-type SPD. Through analysis and simulation, it is verified that the active triggering circuit can reduce the breakdown voltage of the switching-type SPD without impacting the original protection performance. Through further analysis, it is found that adjusting the parameters of the MOV in the triggering circuit will have a positive influence on the voltage protection level of the switching-type SPD. The conclusion of the paper can provide a reference for the selection of the MOV in the triggering circuit.