Toward the ITER neutral beam (NB) system operating at DC -1 MV, several insulating techniques with oil, gas (air, SF6) and in vacuum have been developed. For the NB Test Facility (NBTF) established in Padua (Italy), the DC 1 MV power supply (PS) components such as transformers, transmission line, HV Deck and HV bushing have been manufactured, installed and the on-site acceptance tests have started to ensure compliance with the ITER requirement in advance of the ITER. The 1 MV acceleration voltage to produce deuterium negative ion beams with 1 MeV, 40 A for 3600 sec is obtained with five-stage (200kV each) DC generator (transformer and rectifier) and transmitted to the beam source in a single SF6-gas insulated transmission line (pressurized tanks) with length of ~100 m. During the installation of the transmission line, increase of contact resistance at connection points of the inner conductor inside the transmission line were observed. For such a long component, the tanks cannot be closed just after connecting the conductor. Thus, exposure to the air for several months induced the increase of the contact resistance. To avoid an electric and thermal impact on high-current conductors, a recovery technique of the contact resistance without disconnection was investigated. Finally, most of PS component have been installed and the voltage holding test for each section of the PS system as the on-site acceptance test has started. In this paper, recent progress of voltage holding test of the ITER NBTF DC 1 MV high-voltage PS including European component is reported.
Achievement of DC 1 MV Insulation in High-Voltage Power Supply for ITER Neutral Beam Test Facility
Toigo V;
2019
Abstract
Toward the ITER neutral beam (NB) system operating at DC -1 MV, several insulating techniques with oil, gas (air, SF6) and in vacuum have been developed. For the NB Test Facility (NBTF) established in Padua (Italy), the DC 1 MV power supply (PS) components such as transformers, transmission line, HV Deck and HV bushing have been manufactured, installed and the on-site acceptance tests have started to ensure compliance with the ITER requirement in advance of the ITER. The 1 MV acceleration voltage to produce deuterium negative ion beams with 1 MeV, 40 A for 3600 sec is obtained with five-stage (200kV each) DC generator (transformer and rectifier) and transmitted to the beam source in a single SF6-gas insulated transmission line (pressurized tanks) with length of ~100 m. During the installation of the transmission line, increase of contact resistance at connection points of the inner conductor inside the transmission line were observed. For such a long component, the tanks cannot be closed just after connecting the conductor. Thus, exposure to the air for several months induced the increase of the contact resistance. To avoid an electric and thermal impact on high-current conductors, a recovery technique of the contact resistance without disconnection was investigated. Finally, most of PS component have been installed and the voltage holding test for each section of the PS system as the on-site acceptance test has started. In this paper, recent progress of voltage holding test of the ITER NBTF DC 1 MV high-voltage PS including European component is reported.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
