取消人工接地体对特高压同塔双回线路反击闪络特性的影响  

Impact of Canceling Artificial Grounding Electrode on the Back-flashover Characteristics of UHV Double-circuit Transmission Line

作　　者：何俊佳[1] 杨瑞[1] 贺恒鑫[1] 陈维江[2] 赵贤根[1] 沈海滨[3] 

机构地区：[1]华中科技大学电气与电子工程学院强电磁工程与新技术国家重点实验室,武汉430074 [2]国家电网公司,北京100031 [3]中国电力科学研究院,北京100192

出　　处：《高电压技术》2016年第11期3421-3428,共8页High Voltage Engineering

基　　金：国家电网公司科技项目(GY71-14-064;GY71-14-007)~~

摘　　要：为准确分析取消人工接地体后特高压同塔双回线路的反击闪络性能,探讨取消人工接地体的适用条件,以我国浙北—福州特高压工程同塔双回线路为研究对象,基于时域有限差分法和先导闪络判据,分析了不同呼高和土壤电阻率下的反击闪络特性。结果表明:取消接地体会使绝缘子两端过电压波尾和峰值抬升,越靠近地面的相抬升越厉害;闪络间隙电压抬升效果主要受土壤电阻率影响,随着土壤电阻率增加,取消接地体后闪络间隙电压的抬升效果越明显,当土壤电阻率大于1 500?·m时,中相比上相更容易发生闪络;在土壤电阻率不超过500?·m的地区取消人工接地体,则可以保证耐雷水平大于200 k A。To accurately analyze the back-flashover characteristics for canceling artificial grounding electrode in UHV double-circuit transmission line and discuss the suitable conditions for canceling artificial grounding electrode, we investigated the back-flashover characteristics of Zhebei-Fuzhou UHV double-circuit transmission line based on finite difference time domain（FDTD） method and leader flashover criterion by considering different tower height and soil resistivity. The results show that wave tail and peak value of the insulator string voltage will rise by canceling artificial grounding electrode. The closer the power line to the ground is, the more the gap voltage rises. The rising effect mainly depends on the soil resistivity. With the increase of soil resistivity, the effect of flashover gap voltage rise by canceling artificial grounding electrode is more remarkable. Especially, the air gap between middle phase of the power line and the lower cross arm is more likely to breakdown than the air gap between upper phase of the power line and the middle cross arm when the soil resistivity exceeds 1 500Ω/m^2. We can cancel artificial grounding electrode when the soil resistivity is under 500Ω/m^2 to guarantee the lightning withstand level exceeding 200 kA.

关 键 词：特高压同塔双回线路 绝缘子串过电压 反击闪络特性 耐雷水平 人工接地体 时域有限差分法 

分 类 号：TM863[电气工程—高电压与绝缘技术] TM75