【作者】 周远翔； 张云霄； 张旭； 刘睿； 王明渊； 高胜友； 张博雅；

【Author】 ZHOU Yuanxiang;ZHANG Yunxiao;ZHANGXu;LIURui;WANG Mingyuan;GAO Shengyou;ZHANG Boya;State Key Lab of Control and Simulation of Power Systems and Generation Equipments, Dept of Electrical Engineering, Tsinghua University;

【机构】 清华大学电机系电力系统及发电设备控制和仿真国家重点实验室；

【摘要】 电缆系统长期运行在高温下会对新型超高压预制式电缆附件主绝缘材料硅橡胶(SIR)的性能产生影响。针对电缆长期最高运行温度(90℃)下热老化时间对硅橡胶材料电树枝老化特性的影响展开试验研究,测定90℃温度场下老化1000h对硅橡胶材料电树枝老化特性的影响规律,并进行理论分析。试验结果表明,90℃热老化作用下,硅橡胶随着老化时间的增加,起树电压出现先增再减的趋势。硅橡胶电树枝形态与老化时间密切相关,老化过程中树枝状比例很低,随着老化时间增加,丛状树枝比例先增再减,松状比例先减再增。另外,通过对最大放电量的测试可以发现,最大放电量的变化随时间先减再增。结合差热分析、平衡溶胀等实验对试验进行分析讨论后认为,90℃下硅橡胶交联网络破坏是硅橡胶起树电压大幅下降,电树枝形态改变的重要原因。运行温度下的热老化对硅橡胶的性能产生了严重的影响,需要引起重视。更多还原

【Abstract】 Power cable operates at high temperature over a long period, which has influence on the electrical performance of silicone rubber(SIR) in the new types of extra high voltage prefabricated cable accessories. In this paper, tests were conducted to reveal the relationship between the thermal aging time(0 h-1000h) at 90°C and the electrical tree aging characteristics. Results show that the electrical tree initiation voltage first increases and then decreaseswithtime going. It is found that the thermal aging time has great effect on the characteristics of electrical tree. With the thermal aging time going, the probability of pine-like tree first decreases then increases, while the probability of bush-like tree first increases thendecreases, and the probability of branch-like tree is always low. It is also found that the maximum discharge capacity first decreases then increases. Combined with the experiment of Differential Scanning Calorimetry(DSC) and Equilibrium Swelling, it is believed that the breakdown of cross-linking network in SIR causes all changes above. We should pay more attention to the effect of thermal aging.更多还原