高压直流接地极对埋地管道的干扰及防护研究

摘要

高压直流输电线路与埋地管道路由选择的相似性导致管道不可避免地进入高压直流干扰影响区.为探究公共走廊内高压直流接地极对埋地管道的干扰与防护规律,采用边界元软件计算了不同防腐层破损率 、不同管道到接地极距离下的高压直流干扰强度,分析了分段绝缘措施和缓解锌带的防护效果.结果表明,防腐层均匀破损率越小,干扰电流越集中,局部腐蚀风险越高;绝缘法兰之间的管段受到的干扰得到缓解,而隔离区外管段受到的干扰加剧;缓解锌带的保护范围有限,与锌带长度相当.最后,提出了分段绝缘 、阴极保护 、缓解锌带相结合的综合防护措施.%Due to the similarity of the routing between HVDC transmission lines and buried pipelines ,the local pipelines inevitably enter the HVDC transmission interference zone .In order to study the law of interference and mitigation of HVDC grounding electrode on buried pipeline ,boundary element software was used to calculate the effectiveness of various mitigation methods including anti-corrosion coating ,the distance between the pipeline and the grounding electrode ,insulating joints and zinc ribbon .The results indicated that the smaller the coating breakdown factor was ,the more concentrated the interference current was ,and the higher the local corrosion risk was .After installing the insulating joints ,the strongest interfered section of pipe was alleviated ,while the interference of the other section of pipe was aggravated .The protection range of the zinc ribbon was equivalent to the length of the zinc ribbon .Finally ,the paper put forward the comprehensive protection measures which included insulating joints ,cathodic protection and zinc ribbon .