Experimental Analysis of Lightning Overvoltages Induced on Low-Voltage Distribution Lines

Abstract

Problems have been often caused in low-voltage distribution lines such as single phase 100/200V and three-phase 200 V systems. For instance, the burning of low-voltage devices and the unnecessary operation of ground fault interrupters have occured, which are possibly caused by lightning overvoltages.
Experimental analysis was performed on the generation modes of lightning overvoltages on low-voltage distribution lines.
A scale model line, 1/4 the size of an actual power distribution line of Tokyo Electric Power Company (TEPCO) was installed for experimental analysis on the lightning protection of an overhead ground wire, an overhead common grounding wire (system neutral conductor), surge arresters and pole transformers against the overvoltages induced on low-voltage distribution lines due to nearby lightning stroke.
A baloon was flown at a location 30 m apart from the scale model line in a normal direction to it. A wire of 200m long is suspended from the baloon to simulate a lightning path. Pulse current is applied to the simulated path using a pulse generator and the voltages induced on the line conductors are measured.
This paper analyzes those overvoltages by means of the experimental and the theoretical methods.