同走廊多回超高压输电线路对平行接近高速公路机电系统的电磁影响及防护措施

Electromagnetic Influences of Multi-Circuit EHVAC Transmission Lines Arranged in Same Corridor on Electromechanical Systems of Expressways Parallelly Adjacent to the Corridor and Prevention Measures

当高速公路平行接近共用走廊的多回超高压输电线路时,高速公路机电系统的通信光缆和低压电缆需面对输电线路短路故障时产生的强大磁感应和地电位升的考验。为保障高速公路机电系统的安全运行,提出综合防护方案,包括输电线路上架设良导体架空地线,机电系统的通信光缆采用无金属光缆,低压电缆尽量远离输电铁塔以及采用高耐压电缆并加装过电压保护器等。采用这些措施,可以改善共用走廊的电磁环境,提高机电系统承受电磁影响的能力,从而增强高速公路安全运行的可靠性,为土地资源稀缺地区实现多回输电线路与高速公路共用走廊的规划提供技术方案。

When expressway is adjacent to the corridor in which multi-circuit extra high voltage AC （EHVAC） transmission lines are arranged, the communication optical fiber and low voltage cables in electromechanical system of the expressway have to be faced with strong magnetic induction and earth potential rise while short-circuit fault occurred in the transmission lines. To ensure the secure operation of electromechanical system of the expressway, a synthetical protection scheme is proposed, which includes erecting overhead ground wire with good conductivity, substituting communication optical fibers of the electromechanical system by metal-free optical cables, making low voltage cable far away from transmission towers as possible, adopting cables that can withstand high voltage and installing over-voltage protector. Using these measures the electromagnetic environment parallelly adjacent to the common corridor can be improved and the ability of the electromechanical system to endure the electromagnetic affects can be strengthened, thus the reliability of secure operation of expressway can be enhanced. The proposed measures are available for reference to offer technical scheme for power network planning, in which the transmission corridor is in common used by multi-circuit transmission lines and expressway, for the regions where the land resources are scarce.