交流输电线路单相接地故障下油气管道交流干扰的缓解

Mitigation of AC Interference on Oil and Gas Pipelines Due to Single-phase Earth Fault in AC Transmission Line

交流输电线路发生单相接地故障时会对"公共走廊"内的油气管道产生严重的交流干扰,危害人身安全、管道涂层及管道相关设备。因此,有效的缓解技术对于减小油气管道的交流干扰,保证人身安全和管道完整性具有重要的意义。以东营某油气管道为模型,对交流输电线路单相接地故障下油气管道交流干扰进行了系统的分析,提出了故障点处阻性耦合交流干扰的最佳缓解线长度计算公式;阻性耦合交流干扰的可缓解范围以及在可缓解范围内其他区域实施缓解时为达到与故障点处缓解相似的缓解效果所需缓解线长度的估算公式;提出综合缓解感性和阻性耦合交流干扰时应充分考虑两者之间的相位差。

AC interference on oil and gas pipelines near AC transmission line because of the single-phase earth fault of AC transmission line will threaten the personnel safety, the coating on pipelines and relevant facilities. Hence, effective mitigation techniques are required to reduce the risk of AC interference to the levels that are safe for the personnel and integrity of pipelines. Based on a practical common corridor in Dongying, China, AC interference on buried pipelines under the single-phase earth fault condition was analyzed systematically; the formulas for optimum length and mitigation area of mitigation wire for AC interference at fault site due to conductive coupling were presented. The formulas for required length of mitigation wire installed in other sites within the mitigation area were presented in order to ensure a similar mitigation effectiveness as the mitigation wire installed at the fault site. Moreover, the mitigation methodology considering phase difference between conductive coupled and inductive coupled AC voltages on buried pipelines was presented.