Waveform Analysis of Lightning Induced Overvoltages on 10 kV Distribution Lines

Abstract

Lightning induced overvoltage is an important cause of fault in distribution network, and it is also the culprit of electrical equipment damage. The former research mode about overvoltage of distribution lines is mainly using shrinkage model or simulation calculation, and lack of measured results as evidence. The On-line overvoltage monitoring system was used to monitor phase conductor overvoltage of distribution lines, including lightning overvoltage, internal overvoltage and electromagnetic transient on 10 kV distribution line in Foshan, the system recorded 61 lightning overvoltage records in 2016 on the 10kV Maning Line, and the number of return strokes was up to 17 times. The average positive peak value is about 5 kV, while the negative peak value is slightly smaller than the positive peak value. Whether positive or negative, the overvoltage amplitude of phase B is always the lowest and that of phase A is always the highest. The average 10%-90% rise time is about 5 μs and the average duration time is about 10 μs. The peak value of measured induced overvoltage is much lower than that calculated by the Rusck's model.