Busbar monitoring system of the ITER DC busbars

In ITER, DC busbars will be used to connect the AC/DC converters to the superconducting coils of the magnet system; the total length will exceed 5 km. The busbars used in the TF, PF/CS and CC coil power supply systems are rated for continuous current up to 68 kA, 55 kA and 10 kA respectively. The busbars will be cooled by deionized water through inlet and outlet cooling water collectors. The water flow rate and temperature will be measured by sensors installed in outlet collectors because reduction or loss of water flow might cause excessive heating of the busbar conductors and, in extreme case, damage their insulation. To prevent this, the Busbar Monitoring System was developed at the Efremov Institute for continuous monitoring of thermal conditions of the busbars. This paper presents the architecture of the Busbar Monitoring System, the detailed description of its components and results of their testing. The successful results of the type tests confirmed suitability of the design and compliance with ITER requirements which together with completion of the final design review makes it possible to start manufacturing of Busbar Monitoring System components for delivery to the ITER Site.