基于电网络法的特高压交流悬式瓷绝缘子串均压环的研究

特高压交流输电线路悬式单垂瓷绝缘子串在无均压环时导线侧前两片的电压承担率分别为14.4%和11.1%,其电压分布极不均匀。利用电网络法对特高压悬式瓷绝缘子串均压环的尺寸及罩入深度进行了优化计算。结果表明:为了达到更好的均压效果,均压环对绝缘子的杂散电容应在不超过33!F时尽量大;两端应各安装一个均压环,其罩入深度为三片绝缘子时,均压效果最好;在工程中,应选用三角形排列酒杯塔,以减小三相绝缘子串电压分布的不一致性。

Studies on Corona Rings for UHV Lines Insulator Strings based on Electrical Network Method

The first two insulator units at line end of UHV insulator string without corona rings bear extremely uneven voltage stress of about 14.4%and 11.1% respectively. The size and cover depth of corona rings of UHV suspension porcelain insulator stings were calculated by electric-network method. The results showed that for a better voltage distribution, the stray capacitance between corona ring and insulators should be large enough within limit of 33 F to obtain best distribution, which appeared when corona rings were installed at 3-unit-long cover depth at both ends of insulator string. It is suggested that triangle cup tower should be chose in engineering practice to minimize unconsistency of voltage distribution between string of 3 phases.