Influences of the length of connecting leads on the coordination performance of cascaded SPD systems

초록

For the purpose of designing and applying optimum surge protection, multi-stage coordinated surge protective device (SPD) system is suitable to successfully fulfill these tasks; first, to divert a large amount of transient energy; second, to clamp the overvoltage to a level below that of the withstand impulse voltage of the equipment to be protected. The length of SPD connecting leads should be as short as possible. Long leads will degrade the protection effect in coordinated SPD systems. In this paper, the influences of the length of connecting leads on the current sharing in two-stage SPD systems were investigated experimentally, and simulation of determining the energy sharing and protection voltage level of SPDs depending on the length of connecting leads was carried out by using P-spice software. It was confirmed that the protection voltage level and energy sharing in coordinated SPD systems are strongly influenced by the length of connecting leads.