Flexible Gas-Insulated Cable for 230 kV, 345 kV and 500 kV

An 80-meter section of 345 kV flexible cable has been designed, manufactured, tested and installed at EPRI Waltz Mill Cable Test Facility for long-term testing. Complete dielectric tests have been carried out on other sections of this 390 mm cable which verify its 345 kV rating. Sections of 330 mm (230 kV) cable have also been manufactured and tested. The design for 500 kV cable has been prepared based on the experience at 345 kV and 230 kV. The advantages of this flexible gas-insulated transmission line are, 1) its ability to be made in long lengths at low manufacturing cost, 2) its ability to be pulled into and conform to irregular trenches, and 3) its ability to be shipped in long reeled lengths, thereby reducing field assembly costs and improving reliability.