A Design Study on 40 MW Synchronous Motor with No-Insulation HTS Field Winding

Uijong Bong, Soobin An, John Voccio, Jaemin Kim, Jung Tae Lee, Jihoon Lee, Ki Jin Han, Haigun Lee, Seungyong Hahn

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)


This paper presents a design study on a 40 MW synchronous motor having no-insulation (NI) high-temperature superconductor (HTS) field coils. An in-house analytic code was used to obtain a first-cut design based on the published parameters of the AMSC 36.5 MW ship propulsion motor as a reference. Then, design refinement was followed using the finite-element method to more accurately simulate electromechanical behaviors of the motor. After the final design was completed, transient torque responses of the NI motor, in no load and full load conditions, were simulated with our new equivalent circuit model to consider the nonlinear behaviors of the NI field coils, and compared the results with those of its insulated counterpart. The overall torque response of the NI machine was essentially identical to that of the insulated one, though a notable discrepancy was observed at the moment when the rotor acceleration started and ended. The results may imply that the NI field coils play a role as an effective damper in perspective of the torque response. The results demonstrate a potential to use the NI HTS field coils for a low-speed synchronous machine such as the ship propulsion motor.

Original languageEnglish
Article number8678457
JournalIEEE Transactions on Applied Superconductivity
Issue number5
Publication statusPublished - 2019 Aug
Externally publishedYes

Bibliographical note

Funding Information:
Manuscript received October 30, 2018; accepted March 22, 2019. Date of publication April 1, 2019; date of current version April 30, 2019. This work was supported by the National Research Foundation of Korea as a part of Mid-Career Research Program under Grant 2018R1A2B3009249. (Corresponding authors: Seungyong Hahn and Haigun Lee.) U. Bong, S. An, J. Kim, J. T. Lee, and S. Hahn are with the Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Republic of Korea (e-mail:,hahnsy@snu.ac.kr).

Publisher Copyright:
© 2002-2011 IEEE.


  • HTS synchronous motor
  • no-insulation field coil
  • parameter sweep
  • transient response

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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