Calculation and simulation of mechanical pressure of XLPE-SR surface in cable joints

Abstract

Interfacial breakdown in cable accessories can lead to high voltage cable fault. One of the paramount factors of interfacial electric strength is interfacial mechanical pressure, which depends on the magnitude of interference and variates with the operating temperature. Since the growing industry of cable accessory lacks a unified standard for interfacial pressure, accessory products differ in a range of sizes, resulting in different initial interfacial mechanical pressure. With the difficult measurement of interfacial pressure, the uncertain initial pressure brings higher degree of uncertainty during operation, as high pressure can cause the deformation of insulation while low pressure cannot guarantee the interfacial electric strength. In this paper, theoretical calculation of the interfacial mechanical pressure is conduct and verified by simulation. The impact of high temperature on the mechanical pressure is also shown in the simulation results.