Study of Partial Discharge in Pressboards

Abstract

Study of partial discharge plays an important role in the aging and the rupturing process of solid and mixed insulation systems. The PD analysis is a predictive test which indicates insulation degradation in advance, which may lead to the failure of the system, and it is performed under normal operating conditions. Pressboards are solid insulating materials made by compressing layers of paper together and drying them. They are used in bushings and in transformers as insulating barriers or supporting materials. The main advantage of this material is that it provides good mechanical support even at higher temperatures up to 120 °C. It has a high degree of flexibility, simultaneously possessing high tensile and compression strength. This paper presents the experimental study conducted on the prepared sample using pressboards as the solid insulating sheet and the effects of different parameters such as pressure, temperature, curing period, and number of conducting layers on partial discharge in the insulating sheet.