-1 MV DC UHV Power Supply for ITER NBI
نویسندگان
چکیده
Abstract. Japan Atomic Energy Agency as the JApan Domestic Agency (JADA) for ITER and the Domestic Agency of EU (EUDA) agreed the procurement sharing for the ITER NBI power supply system. The JADA contributes procurement of dc -1 MV ultra-high voltage (UHV) components such as a -1 MV dc generator, a transmission line and a -1 MV insulating transformer. The dc UHV insulation has been carefully analyzed since dc long pulse insulation is quite different from conventional ac insulation. Voltage sharing varies from capacitive distribution to resistive one during long pulse dc application. Electric field distribution for multi-layer (oil/paper composites) insulation structure of the transformer has been investigated for a long pulse dc up to 3600 s. The insulation structure has been designed and the overall dimensions of the dc UHV components have been finalized. A surge energy suppression system is also essential to protect the accelerator from electric breakdowns. The JADA contributes to provide an effective surge suppression system composed of core snubbers and resistors. Input energy into the accelerator from the power supply can be reduced to about 20 J which satisfies the design criteria of the total 50 J at -1 MV breakdown. From these studies, major technical issues were considered and the functional technical specifications of the UHV components have been developed for the procurement by the JADA.
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