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Development of a 400 kJ Nb 3 Sn superconducting magnet for an SMES system
Author(s) -
Harada Naoyuki,
Toyoda Katsuyoshi,
Minato Tsuneaki,
Ichihara Tadashi,
Kishida Takuya,
Koike Tatsuo,
Izumi Toru,
Murakami Yoshishige
Publication year - 1997
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/(sici)1520-6416(19971130)121:3<44::aid-eej6>3.0.co;2-x
Subject(s) - electromagnetic coil , materials science , cryostat , cryocooler , conductor , magnet , superconducting magnet , liquid helium , electrical conductor , superconducting magnetic energy storage , superconductivity , joule heating , coil tap , nuclear magnetic resonance , electrical engineering , rogowski coil , mechanical engineering , composite material , condensed matter physics , helium , physics , engineering , atomic physics
An Nb 3 Sn superconducting magnet to store 400 kJ was developed as a unit magnet for a 2.4‐MJ SMES system used for stabilization studies of electrical power systems. The superconducting magnet consists of a cryostat and an Nb 3 Sn coil. The dimensions of the coil are: 340 mm inner diameter, 700 mm outer diameter and 177 mm axial length. The pool‐cooled coil is a stack of 20 Nb 3 Sn double pancakes, and the cooling channels are aligned between pancake coils. To reduce Joule loss in electrical power converters, the maximum operating current of the coil is designed to be 350 A, which is one order of magnitude less than the operating currents of similar scale coils for pulse use. The conductor is an Nb 3 Sn monolithic conductor with cross section 1.50 × 2.38 mm. For good superconducting stability and high dielectric strength of the coil, the Nb 3 Sn double pancakes were wound by the react‐and‐wind technique. Operation of dc current to 105% (367.5 A) of the design operating current was achieved without quench. After the whole of the coil was exposed out of liquid helium, the coil did not quench under 120 A current operation for more than 2 hours. It was verified that the coil was stable for the SMES system. © 1998 Scripta Technica, Inc. Electr Eng Jpn, 121(3): 44–52, 1997