高压电器2025，Vol.61Issue(2)：102-110,9.DOI:10.13296/j.1001-1609.hva.2025.02.012
高低温和硬度对电缆附件硅橡胶材料绝缘性能的影响及机理分析
Influence of Hot-cold Temperature and Hardness on Insulation Performance of Silicone Rubber Material of Cable Accessories and Mechanism Analysis
摘要
Abstract
Temperature is the key factor affecting the insulation performance of cable accessories.In this paper,the infrared spectrum and glass transition characteristics of silicone rubber materials with different hardness are ana-lyzed,and the dielectric properties,resistance properties and breakdown properties of the silicone rubber materials with different hardness for cable accessories are tested and analyzed under high and low temperature environment from-40℃ to+60℃.From the micro level,the influence mechanism of high and low temperature on the insulating property of silicone rubber is revealed by calculating and analyzing the free volume and mean-square displacement of silicone rubber at different temperatures.The research shows that with the increase of temperature,the relative di-electric constant of silicone rubber with hardness of 40 HA is decreased from 3.66 to 3.22,that is about 12%.In con-trast,the relative dielectric constant of silicone rubber with hardness of 90 HA is decreased about 15%.The tangents of the dielectric loss angles of the two remain almost unchanged in the range of-40℃ to+60℃,with the average val-ues of 1.46×10-3 and 1.57×10-3,respectively.The reason is that with the rise of temperature,the mean-square displace-ment of silicone rubber molecules increases,and the bound charge polarization process is hindered by the disordered movement.In addition,the increase of silica content can improve the dielectric constant of the silicon rubber with hardness of 90 HA.With the rise of temperature from-40℃ to+60℃,the volume resistivity of the silicon rubber with hardness of 40 HA is decreased from 1.24×1017 Ω·cm to 1.14×1015 Ω·cm.At the same temperature,the volume resistivity of the silicon rubber with hardness of 90 HA is decreased by about 1 order of magnitude.This is mainly related to the carrier concentration due to temperature,mobility variation and the content of silica.With the rise of temperature from-40℃ to+60℃,the breakdown strength of the silicone rubber with hardness of 40 HA is decreased from 39.29 kV/mm to 23.98 kV/mm with reduction of approximately 39%,and that with hardness of 90 HA is slightly decreased at the same temperature.This is because the free volume of the silicone rubber increases with the increase of temperature,resulting in larger free travel of electrons,and more energy is obtained by free electron accel-eration.At the same time,the introduction of silica as an impurity will lead to an increase of the breakdown probabili-ty of silicone rubber at the weak point.This work has guiding significance for abnormal analysis and performance improvement of cable accessories.关键词
电缆附件/硅橡胶/高低温/硬度Key words
cable accessories/silicon rubber/hot and cold temperature/hardness引用本文复制引用
张帆,王景兵,齐朋帅,周旭光,张连康,王家兴,魏艳慧,李国倡..高低温和硬度对电缆附件硅橡胶材料绝缘性能的影响及机理分析[J].高压电器,2025,61(2):102-110,9.基金项目
山东省高等学校"青创科技支持计划"项目(2021KJ023).Project Supported by Shandong Province Universities Youth Innovation Technology Support Plan(2021KJ023). （2021KJ023）
