输电线路杆塔地网冲击接地电阻现场测量方法  

On-Site Measurement Method of Impulse Grounding Resistance of Transmission Tower Grounding Network

作　　者：刘溟[1,2] 曹斌[2] 郑俊杰[1] 杨帅[2] 涂长庚[1] 喻剑辉[2] 周文俊[2] 

机构地区：[1]华中电网有限公司,武汉430077 [2]武汉大学电气工程学院,武汉430072

出　　处：《电瓷避雷器》2014年第4期37-42,共6页Insulators and Surge Arresters

基　　金：国家自然科学基金资助项目(编号:51277136)

摘　　要：为研究杆塔地网冲击特性,掌握冲击电阻值的变化,提出了一种杆塔地网冲击接地电阻现场测量方法,采用适于现场使用的冲击电流发生器产生大电流、陡波头的冲击电流模拟雷电流,使地网电感效应与火花效应得以体现。利用实验室变电站地网对该方法进行验证与改进:在电压测量回路首段接入300Ω阻尼电阻消除电压波形振荡;通过降低回流极接地电阻增大电流幅值。现场试验在湖北省武汉市某变电站500 kV交流线路进线侧2号杆塔进行,冲击接地电阻随电流幅值的增大呈非线性下降趋势。实验室与现场试验表明:该方法可有效测量杆塔地网冲击接地电阻。To study impulse characteristics of tower grounding network and grasp the change of impulse resistance,a test method of impulse grounding resistance of tower grounding network is proposed, which uses impulse current generator to produce large and steep wave front impulse current to simulate lightning current reflecting inductive effect and spark effect. The method is validated and improved by making use of laboratory substation grounding grid：300 Ω damping resistance is connected in the first paragraph of voltage measurement circuit to eliminate voltage waveform oscillation; current amplitude is increased by reducing the grounding resistance of backflow pole. Field trials is carried out in Wuhan,Hubei Province,in a substation 500 kV AC line cord into the side of the 2nd tower,the impulse grounding resistance presents a downward trend in non-linear with the increase of current magnitude. Laboratory and field test obtained that,the impulse grounding resistance of the tower grounding network can effectively measured by this method.

关 键 词：杆塔 冲击接地电阻 冲击电流发生器 阻尼电阻 冲击特性 

分 类 号：TM862[电气工程—高电压与绝缘技术]