Research on Discharge Early Warning of Tree-related Hidden Dangers in Transmission Lines Based on Traveling Wave Monitoring

Abstract This paper summarizes the research status of hidden danger early-warning for transmission lines, analyzes the existing research methods and applications of hidden dangers such as tree-related ones, bird nests on lines, and foreign objects attached to conductors, and proposes a new early-warning method based on the traveling-wave discharge characteristics. Through simulation experiments, the discharge waveforms of tree-related hidden dangers at different distances are obtained. The distribution of characteristic parameters of the discharge waveforms in different development stages of trees is studied. Four characteristic parameters, namely amplitude, number of pulses, pulse energy, and phase interval, are calculated and assigned values one by one. The results show that when the net distance between the tree and the line gradually decreases, the discharge amplitude, the number of discharge pulses, the discharge pulse energy, and the initial discharge phase difference generally show an increasing trend, and this increasing trend is more obvious at higher voltage levels. The main frequency of tree discharge pulses presents a wavy-line distribution, mostly concentrated within 1-2 MHz. Therefore, the discharge risk level of tree-related hidden dangers can be calculated according to the discharge data characteristics of trees in different development stages, realizing the hierarchical early-warning of tree-related hidden dangers.