High Voltage Behaviour of Large Size Air Insulated Coaxial Transmission Line

Mega watt particle accelerators like Neutral Beam Injectors draw electrical power for Plasma formation, Ion Extraction at elevated potential of ~100kV, infact the water cooling lines, gas feed lines are also floating at 100kV. Usually power supplies, hydraulic/gas feed station of typical Injector are placed in a separate building/location. In such a scenario, large coaxial transmission lines are used to support power transport, hydraulic & gas feed lines, providing electrical isolation of 100kV. This paper presents electrostatic analysis for the complex configuration of large transmission line. Specially designed profiles to provide electrical isolation within permissible limits of electric stress. Further HVDC test results showing behaviour of Transmission line over longer exposure of 3600s are also presented.