AC Compact High Power Gas-Insulated Transmission Lines

The AC Gas-Insulated Transmission Lines (GIL) technology for high power underground transmission shows an ever-increasing usage worldwide. Today, the AC GIL transmission technology is entering densely populated areas where the desire for solutions of non-visible transmission lines is high. AC GIL provides a powerful solution for underground installations. The next step in development of AC GIL is focused on increasing the level of automated laying procedures using the mobile factory as a flexible and effective laying machine. The mobile factory contains the friction stir welding machine for high quality welding of the enclosure and conductor pipes. The laying efficiency of the AC GIL will be improved in total by 20–30% which will reduce the AC GIL project cost. The new concept is set up for long distance applications and allows the localization of major work to the installation site with pre-assembly, assembly and laying works.