日本超高压电缆线路的更换及增容新技术

在日本，作为供电城市的地下电缆电力网络已提升至500kV。这些地下电力电缆连接郊区的发电站/变电站与城市的其他变电站。近年来，老旧的发电厂已被新建的发电厂代替，这就必须提高现有电缆回路的输电容量，以及更换已老化的电缆线路。 绝大部分的日本地下电缆线路都是敷设在电缆沟或隧道之内。为了节约投资和减少在城市建设的难度，最理想的方案是利用现有的电缆沟和隧道，进行增容和更换电缆的工作。 154kV大截面三芯电缆，275kVY-分支接头，水冷却系统的增压水泵等新技术的开发成功，足以满足上述的需求。最近特高压电缆项目成功地采用上述新技术，说明这些新技术被确认进入实用阶段。这些新技术的应用，证明电缆的增容或更换，不需要建新电缆沟或隧道。可以预期，对今后电缆的多种应用具有十分良好的前景。

The new technologies for replacement and up-grating of EHV cable line in Japan

In Japan, underground power cables have been used up to 500kV as transmission networks to supply of electric power to urban areas. These underground power cables connect power plants/substations in suburban areas with other substations in urban areas. In recent years, however, older power plants have been replaced with newer ones, and it has been getting necessary to increase the transmission capacity of the existing circuits and replace the aging underground power cables. Most of underground transmission lines in Japan have been installed in ducts and tunnels. From a perspective of cost reduction and difficulty of construction in urban area, it is highly desirable to increase capacity and replace cable by utilizing the existing ducts and tunnels. 154kV large-sized triplex cable, 275kV Y-branch joint and booster pump for cooling water system were newly developed to meet these requirements. Recently EHV cable projects applying these new technologies have successfully completed confirming their operational practicality. These technologies provide for increased capacity as well as cable replacement without new construction of ducts and tunnels. There is much anticipation regarding their future for a variety of application.