Abstract
Surge protective device is widely used in the lightning protection of electric appliances. In order to meet the withstand voltage level of those protected devices, multi-level surge protective devices are applied in the practical situation. Therefore, the optimal choice of decoupling elements is vital to realize the energy coordination between multi-level surge protective devices. This paper intends to expatiate on the process of coordination between these low-voltage multi-level surge protective devices, which is based on the transmission line theory. Through a series of experiments, we found the transmission line theory could be applied to describe the transmission process of lightning wave in the low-voltage system; When a 5-meter-long wire whose inductance is 5.6 micro-henry was used as the decoupling element, the average shunt ratio between multi-level surge protective device in the first level and multi-level surge protective devices in second was about 0.9: 0.1; upon the experimental results, it was proposed that two voltage limiting type multi-level surge protective devices had a better performance to clamp the overvoltage, which has a certain reference value in the practical application.