Abstract

Capacitively graded oil-paper insulation is a crucial component in many electrical devices, including bushings and instrument transformers. Despite their relatively low cost within the electrical energy supply system, failures of these devices can lead to significant supply interruptions and economic losses. As such, they represent safety and economic risks that are currently mitigated through robust design, monitoring systems, and preventive maintenance.

With the increasing integration of renewable energy sources, the power grid is more frequently subjected to overvoltage transients. These renewable sources, due to their dispersed and inconsistent nature, increase the frequency of switching operations. Furthermore, the growing use of gas-insulated switchgear has led to a rise in very fast transient phenomena. Recently, for safety and environmental reasons, traditional mineral oils are being replaced with natural or synthetic esters, whose electrical properties are not yet fully understood. As a result, electrical devices are experiencing greater stress, making it imperative to investigate the impact of these phenomena on their insulation.

This project aims to construct a model housing designed to test very fast transient phenomena and to establish an experimental setup capable of producing and measuring all types of voltage transients. By examining influential and control parameters, the project will develop a detailed test plan to thoroughly investigate the impact of these phenomena on capacitively graded oil-paper insulation. The study will consider different materials for capacitive layers and various types of oil.

The project is expected to enhance understanding of the behaviour of capacitively graded oil-paper insulation under transient conditions. This knowledge will contribute to optimizing the design and monitoring of electrical devices, thereby improving their safety and reducing their environmental footprint.