Work and safety managements for on-site installation, commissioning, tests by EU of quench protection circuits for JT-60SA

Yamauchi, Kunihito; Okano, Jun; Shimada, Katsuhiro; Omori, Yoshikazu; Terakado, Tsunehisa; Matsukawa, Makoto; Koide, Yoshihiko; Kobayashi, Kazuhiro; Ikeda, Yoshitaka; Fukumoto, Masahiro; et al.

JAEA-Technology 2015-053, 36 Pages, 2016/03

JAEA-Technology-2015-053.pdf:8.33MB

The superconducting Satellite Tokamak machine "JT-60SA" under construction in Naka Fusion Institute is an international collaborative project between Japan (JA) and Europe (EU). The contributions for this project are based on the supply of components, and thus European manufacturer shall conduct the installation, commissioning and tests on Naka site. This means that Japan Atomic Energy Agency (JAEA) had a quite difficult issue to manage the works by European workers and their safety although there is no direct contract. This report describes the approaches for the work and safety managements, which were agreed with EU after the tough negotiation, and then the completed on-site works for Quench Protection Circuits (QPC) as the first experience for EU in JT-60SA project. With the help of these approaches by JAEA, the EU works for QPC were successfully completed with no accident, and a great achievement was made for both EU and JA.

First switching network unit for the JT-60SA superconducting central solenoid

Lampasi, A.*; Zito, P.*; Coletti, A.*; Novello, L.*; Matsukawa, Makoto; Shimada, Katsuhiro; Burini, F.*; Kuate-Fone, Y.*; Taddia, G.*; Tenconi, S.*

Fusion Engineering and Design, 98-99, p.1098 - 1102, 2015/10

https://doi.org/10.1016/j.fusengdes.2015.06.177

Overview of the new magnet power supply systems of JT-60SA procured by EU

Novello, L.*; Baulaigue, O.*; Coletti, A.*; Dumas, N.*; Ferro, A.*; Gaio, E.*; Lampasi, A.*; Maistrello, A.*; Matsukawa, Makoto; Shimada, Katsuhiro; et al.

Fusion Engineering and Design, 98-99, p.1122 - 1126, 2015/10

https://doi.org/10.1016/j.fusengdes.2015.06.014

Design and implementation of four 20 kA, 5 kV hybrid switching networks for plasma ignition in the international tokamak JT-60SA

Burini, F.*; Kuate-Fone, Y.*; Taddia, G.*; Tenconi, S.*; Lampasi, A.*; Zito, P.*; Matsukawa, Makoto; Shimada, Katsuhiro; Coletti, A.*; Novello, L.*

Proceedings of 40th Annual Conference of the IEEE Industrial Electronics Society (IECON 2014), p.5035 - 5040, 2014/10

https://doi.org/10.1109/IECON.2014.7049265

Minimization of reactive power fluctuation in JT-60SA magnet power supply

Shimada, Katsuhiro; Terakado, Tsunehisa; Yamauchi, Kunihito; Matsukawa, Makoto; Baulaigue, O.*; Coletti, R.*; Coletti, A.*; Novello, L.*

Plasma Science and Technology, 15(2), p.184 - 187, 2013/02

https://doi.org/10.1088/1009-0630/15/2/22

Resonance characteristics and maximum turn voltage of JT-60SA EF coil

Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Yamauchi, Kunihito; Shimada, Katsuhiro; Terakado, Tsunehisa; Matsukawa, Makoto; Hasegawa, Mitsuru*; Minato, Tsuneaki*; et al.

IEEE Transactions on Applied Superconductivity, 22(3), p.9501405_1 - 9501405_5, 2012/06

https://doi.org/10.1109/TASC.2011.2178010

The withstand voltage of turn insulation is essential issues for the superconducting magnet. The actual turn voltage is larger than the turn voltage under the ideal condition because of the voltage fluctuations of the power supply and the resonance phenomenon in the magnet. In this paper, the voltage measurement of the JT-60U power supply and the resonance characteristics of the EF4 are described. The actual maximum turn voltage is almost same as the voltage under the ideal condition.

JT-60SA power supply system

Coletti, A.*; Baulaigue, O.*; Cara, P.*; Coletti, R.*; Ferro, A.*; Gaio, E.*; Matsukawa, Makoto; Novello, L.*; Santinelli, M.*; Shimada, Katsuhiro; et al.

Fusion Engineering and Design, 86(6-8), p.1373 - 1376, 2011/10

https://doi.org/10.1016/j.fusengdes.2011.02.042

Electric circuit analysis for plasma breakdown in JT-60SA

Yamauchi, Kunihito; Shimada, Katsuhiro; Terakado, Tsunehisa; Matsukawa, Makoto; Cara, P.*; Gaio, E.*; Santinelli, M.*; Coletti, R.*; Coletti, A.*

Journal of Plasma and Fusion Research SERIES, Vol.9, p.220 - 225, 2010/08

Conceptual design of the quench protection circuits for the JT-60SA superconducting magnets

Gaio, E.*; Novello, L.*; Piovan, R.*; Shimada, Katsuhiro; Terakado, Tsunehisa; Kurihara, Kenichi; Matsukawa, Makoto

Fusion Engineering and Design, 84(2-6), p.804 - 809, 2009/06

https://doi.org/10.1016/j.fusengdes.2008.12.100

This paper deals with the conceptual design of the Quench Protection Circuits (QPC) of JT-60SA which have to provide a fast removal of the energy stored in the superconducting coils in case of quench. The core of the QPC units is constituted by a dc current breaker, which diverts the coil current into a resistor for a fast machine de-energization. In this paper, a hybrid solution, composed of a mechanical bypass switch paralleled to a static switch based on Integrated Gate Commutated Thyristor (IGCT) technology, has been chosen and worked out; a pyrobreaker is added in series to the hybrid switch as a backup protection. The resulting design allows benefiting from the fast breaking and very low maintenance requirement of the static switches, besides maintaining the advantage of the much lower power losses of the mechanical bypass in normal operation.

Initial design study of a DC power supply system for JT-60SA

Shimada, Katsuhiro; Omori, Yoshikazu; Okano, Jun; Matsukawa, Tatsuya; Terakado, Tsunehisa; Kurihara, Kenichi

JAEA-Technology 2008-031, 38 Pages, 2008/03

JAEA-Technology-2008-031.pdf:10.84MB

In JT-60SA, Toroidal Field coil (TF coil) and Poloidal Field coils (PF coils) are superconducting coils and a long-pulse plasma operation with more than 100s flattop is assumed. Corresponding to the superconducting TF and PF coils, new DC power supply system in JT-60SA is necessary. The DC power supply system is composed of the reused JT-60 power supply components and newly manufactured ones to reduce total cost. A quench protection circuit is newly introduced to fast discharge coil magnetic stored energy. This paper describes the initial design study of JT-60SA DC power supply system for TF and PF coils in Japan Atomic Energy Agency (JAEA).