复合绝缘子表面异常发热现象分析及其抑制措施

Analysis on Surface Abnormal Heating and the Countermeasure for Composite Insulators

近年来高压输电线路复合绝缘子异常发热频繁发生,对电网安全运行产生严重影响;但目前对其深入研究不够,通常把复合绝缘子异常发热同内绝缘缺陷简单对应,从而盲目采取更换等处理措施,造成人力物力极大浪费。为此,对某500 kV输电线路复合绝缘子大面积异常发热现象进行分析,通过试验分析发现其属于护套表面异常发热,与内绝缘缺陷无直接关联。试验结果表明:随着端部场强增大,异常发热温升增大,表层污秽去除后,异常发热现象消失。提出调整均压环配置来抑制复合绝缘子表层发热,通过带电作业方式实施后,现场运行复合绝缘子异常发热现象明显下降。

In recent years,abnormal heating phenomenon of high voltage composite insulator occurs frequently,which seriously affects the safe operation of power system. Currently,due to lack of deep understanding of abnormal heating,composite insulators which appear abnormal heat were replaced for which usually assumed to have inner insulation defect,this replacement wastes a great deal of human and material resources. Composite insulator samples in AC 500 k V line that had a large scale of abnormal heating were studied,and found that it was kind of sheath surface heating which has no relation with inner insulation defect. The results show that the temperature rise of the composite insulator increased with the rise of field intensity,and the temperature rise disappeared when pollution was washed out. By adjusting the position of the shielding rings of running composite insulators,the temperature rise of the composite insulator decreased significantly.