Properties of Non-Uniform Electric Fields that Contribute to Partial Discharges

Abstract

Partial discharges (PD) can generally be described as electrical insulation breakdown that does not fully penetrate the insulating medium between two conductors. These electrical discharges commonly occur in small voids within an insulator or at the interface between insulators. Over time, PD can degrade and damage important insulation surrounding high voltage wiring or other equipment. The primary goal of this research project is to assist the current low-pressure partial discharge detection research conducted at The Ohio State University’s high voltage laboratory. The results contained herein are divided into three main parts. First, electromagnetic field simulation software has been used to identify electric field patterns that are likely to produce PD. Qualitative comparisons were made between the computer simulation software’s electric field strength graphs and the corresponding location of partial discharge formation found in the laboratory’s low pressure test chamber. Furthermore, the second part compares the two detection devices (an oscilloscope and specialized PD detection computer) used in the high voltage laboratory based upon PD inception voltage to ensure consistency in laboratory measurements. Finally, the PD inception voltage values measured over a wide range of pressures within the test chamber and were compared with established data points from other PD research.