高压输电线路复合绝缘子发热机理的研究

借助于红外热像仪在实验室对含有模拟缺陷的复合绝缘子和来自现场的含有真实缺陷的复合绝缘子拍摄热像图,并与电场强度分布测量结果及解剖结果进行比较分析,研究了复合绝缘子发热的机理,指出内部局部放电引起发热,渗入缺陷的水分带来的介质损耗引起发热,护套严重老化、绝缘电阻下降引起电阻损耗发热这三种发热机理是引起复合绝缘子发热的主要原因,输电线路中的复合绝缘子的发热机理以第三种为主,该研究结果将有利于判断复合绝缘子内部的绝缘缺陷长度及严重程度.

RESEARCH ON HEATING MECHANISM OF COMPOSITE INSULATOR OF HIGH VOLTAGE TRANSMISSION LINE

By means of infrared imager the infrared images of the composite insulators containing simulated defects and those containing real defects from site were taken in the laboratory, and the comparison of these images with both electric field distribution curves and dissection results is performed and analyzed. The heating mechanisms of composite insulators were researched, and three main heating mechanisms, i.e., heating induced by internal partial discharge, heating induced by dielectric loss caused by the water immerged into the defective position, and heating induced by resistance loss caused by serious ageing of the coat and insulation resistance reduction, were pointed out, in which the third one is the main heating mechanism of the composite insulators used in transmission lines. Above research results would be available for judging the length of internal insulation defect of composite insulator and its severity.