基于正交设计法的220kV同塔双回输电线路反击耐雷水平影响因素

Factors Affecting Strike-back Lightning-withstand Level of 220 kV Double-circuit Lines on the Same Tower Based on Orthogonal Experimental Design

为合理选择输电线路的防雷措施，基于数理统计中的正交设计（OED）方法，以某220kV同塔双回线路为例，分析了不同防雷措施对线路反击耐雷水平的提升效果，并对其进行量化处理和权重划分，通过显著性水平F值来表征。计算结果表明，降低杆塔接地电阻、加强线路绝缘、架设避雷线、架设耦合地线、安装线路型避雷器这5种影响因素对线路反击耐雷水平的提升总效应值为14918，各因素的效应值分别为874、710、357、215、12762，显著性水平F值之比为4．07：3．30：1．66：1．00：59．36。当杆塔接地电阻从15Ω降到10Ω、绝缘子片数从15片增加到16片时，线路反击耐雷水平的提升效果最显著。加装线路型避雷器前后，线路的反击耐雷水平分别在64．2-111．9kA和140．和173．7kA之间。

In order to choose lighming protection measures for transmission lines, taking a 220 kV double-circuit trans- mission line as an example, we analyzed the effect of different lightning protection measures enhancing back lightning withstand level based on the orthogonal experimental design （OED） method. The effect was quantified and weighted, and then characterized by the value of significant level, F. According to our calculation, five measures, namely, reducing the grounding resistance of tower, strengthening the insulation of line, setting up ground wire and coupled ground wire, and installing line-type arrester, contributed to improving the striking-back lightning-withstand level with effect values of 874, 710, 357, 215, and 127 62, respectively, 14 918 in total. The ratio ofF among the values is 4.07： 3.30： 1.66： 1.00： 59.36. Meanwhile, decreasing grounding resistance of tower from 15Ω to 10 fΩ and increasing piece number of insulator in- creased from 15 to 16 show the most obvious improving effect. Before and after installing line-type arrester, the striking-back lightning-withstand levels are within 64.2-111.9 kA and within 140.4-173.7 kA, respectively.