Multipoint Measurement of Electric Field in Oil Gap by using Electric Field Measurement Systems based on Kerr Effect

Abstract

Flow electrification phenomenon is one of the most important problems for electrical insulation of oil immersed transformers. In order to clarify the process of the flow electrification phenomenon in detail, the behavior of the electric field and the charge in the oil gaps was investigated by using the multipoint electric field measurement systems based on the Kerr effect. So far, it was thought that the electric field in the oil gap was distributed uniformly under DC stress. It was, however, proved that the field distribution under DC stress wasn't uniform through the multipoint measurement of the field distribution. Further, it was supposed that this field distortion was formed by movement, generation and extinction of the charge in the oil. In this paper, the experimental results and simulations of the electric field distortion phenomenon under DC stress are discussed.