Quench analysis in a 72 kVA superconducting four-winding power transformer

Masataka Iwakuma, K. Funaki, H. Kanetaka, K. Tasaki, M. Takeo, K. Yamafuji

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Quench processes in a 72 kVA superconducting four-winding power transformer were studied experimentally by sudden short-circuiting of the secondary load. An instantaneous decrease in the transport current was observed in both of the primary and secondary main windings during the first half cycle immediately after the short circuit. The equivalent propagation velocity of normal regions along the wire during the period of instantaneous decrease in current was about two orders of magnitude larger than existing theoretical predictions. Two-dimensional propagation of the normal region was also observed after the very fast propagation. In the primary main winding, the equivalent velocity of the very fast propagation was linearly increased with the voltage applied to the normal region of the winding. This type of very fast progagation was explained by a model in which a broad part of the winding is changed into the normal state via a flux-flow state with very low resistivity, due to the excess current. In the secondary main winding, similar fast propagation was also generated by local heating of the winding above a threshold level in the region of the transport current. The experimental results show that the instantaneous transition to the normal state is attributed to a quench process peculiar to superconducting cables, due to the redistribution of the transport current among strands. It is proposed that the abnormal transitions to the normal state can be useful for self-protection of a.c. superconducting windings from burning.

Original languageEnglish
Pages (from-to)1055-1062
Number of pages8
JournalCryogenics
Volume29
Issue number11
DOIs
Publication statusPublished - Jan 1 1989

Fingerprint

Power transformers
transformers
propagation
Superconducting cables
propagation velocity
short circuits
Short circuit currents
strands
cables
wire
Wire
Fluxes
Heating
cycles
electrical resistivity
heating
thresholds
Electric potential
electric potential
predictions

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physics and Astronomy(all)

Cite this

Iwakuma, M., Funaki, K., Kanetaka, H., Tasaki, K., Takeo, M., & Yamafuji, K. (1989). Quench analysis in a 72 kVA superconducting four-winding power transformer. Cryogenics, 29(11), 1055-1062. https://doi.org/10.1016/0011-2275(89)90260-9

Quench analysis in a 72 kVA superconducting four-winding power transformer. / Iwakuma, Masataka; Funaki, K.; Kanetaka, H.; Tasaki, K.; Takeo, M.; Yamafuji, K.

In: Cryogenics, Vol. 29, No. 11, 01.01.1989, p. 1055-1062.

Research output: Contribution to journalArticle

Iwakuma, M, Funaki, K, Kanetaka, H, Tasaki, K, Takeo, M & Yamafuji, K 1989, 'Quench analysis in a 72 kVA superconducting four-winding power transformer', Cryogenics, vol. 29, no. 11, pp. 1055-1062. https://doi.org/10.1016/0011-2275(89)90260-9
Iwakuma, Masataka ; Funaki, K. ; Kanetaka, H. ; Tasaki, K. ; Takeo, M. ; Yamafuji, K. / Quench analysis in a 72 kVA superconducting four-winding power transformer. In: Cryogenics. 1989 ; Vol. 29, No. 11. pp. 1055-1062.
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