高压直流输电系统接地极对西气东输管道的影响

摘要

This study is targeted to investigate the electrical interference of monopolar ground return operation of high-voltage direct current (HVDC) ground electrode in Wengyuan on West-East Phase II gas transmission pipelines.The relationship between the injection current from HVDC ground electrode and the interference potentials on the pipeline was comprehensively analyzed.The results show that at the injection current of 1 200 A,the interference potential on the pipeline reached up to 100 V,and the interference potential shifts were towards opposite direction at the far end (section distant from the ground electrode) and the near end (section close to the ground electrode) of the pipeline,with higher interference severity at the near end than at the far end.The mitigation measures of directly bonding the station and valve chamber grounding system with the pipeline was capable of effectively decreasing the pipeline potential shift at the bonding locations so as to reduce the risk,but meanwhile,increasing the stray current in the pipe at other locations with the interference severity deteriorated accordingly.Therefore,if the station grounding systems are to be used for HVDC interference mitigation,it is strongly recommended that bond sites be properly selected and effectively optimized.%测试了翁源高压直流输电接地极采用单极大地回路方式运行时,对西气东输二线天然气管道的影响,分析了高压直流输电系统中入地电流与管道干扰电位的关系.结果表明:在翁源接地极入地电流为1 200 A时,管道的干扰电位能达到100 V,靠近接地极段管道的电位干扰程度大于远离接地极段管道的,靠近和远离接地极段管道的电位偏移方向相反;站场、阀室接地网与管道直接跨接作为缓解措施,能有效降低跨接位置的管道电位偏移量,降低跨接处的管道风险,但会增大管道中的杂散电流,造成其他管道位置干扰的增加,提高了其他管道位置的风险.因此,采用接地网作为高压直流输电系统接地极干扰的缓解措施,需要进行合理的选点和有效的测试与优化.