Bundled Conductors in Gas-Insulated High Voltage Power Transmission Cables

An improved structure for gas-insulated power transmission cables that employs several subconductors arranged in a bundled configuration is investigated. The study includes electric field calculations, measurements of the breakdown voltages in test lines at different gas pressures, calculations and effects of forces from currents, and an estimation of the heat transfer from the conductors to the outer sheath. The results demonstrate that-compared to equivalent size coaxial lines-the bundled conductor has a lower electric stress on the insulating mechanical supports, is less sensitive to contamination on the spacer surfaces, offers the possibility of trapping contaminating particles inside the bundle, and has a higher heat transfer coefficient