Novel Method to Assess Dielectric Performances of Gas-insulated Electrode Arrangements

To limit climate change and its adverse effects, the world’s primary energy consumption must be decarbonized, which in turn requires electrification of the world’s energy system. High voltage engineering plays a key role in electrification by providing the technology and equipment that enables the transport of electrical energy over longer distances. Many sys-tems important for the transmission and distribution of electrical energy utilize gas-insulated equipment (GIE) filled with pressurized insulation gases (e.g., sulfur hexafluoride, SF6) to achieve the dielectric performance that enables compact, resource-saving designs. Since SF6 is a potent greenhouse gas, research, development, and implementation of SF6 alter-natives is important for the entire high voltage community, including manufacturers and users of GIE. The fact that such equipment is already in demand and in use today highlights the importance of quantifying the perfor-mance of the insulation gases and gas mixtures used for different mixing ratios and pressures. When it comes to dielectrics, one important benchmark regarding electric insulation performance is the insulation of electrodes that have surface de-fects and irregularities, as these may be present in technical applications. To assess this performance, several methods have been established in the past; however, they still often show some am-biguity and variations in their results. Further, they typically depend either strongly on empiricism or on assumptions regarding surface structure. In this paper, a new method is proposed based on three-dimensional surface scans. By means of finite element method software the actual stresses and discharge inception are evaluated on those specific surfaces. Comparison of the results suggests that the method seems to represent dielectric performance fairly well. Further usage of the method, such as investigation of statistical time lag at positive polarity is highlighted.