Quench Protection System for the KSTAR Toroidal Field Superconducting Coil

  • Lee, Dong-Keun ;
  • Choi, Jae-Hoon ;
  • Jin, Jong-Kook ;
  • Hahn, Sang-Hee ;
  • Kim, Yaung-Soo ;
  • Ahn, Hyun-Sik ;
  • Jang, Gye-Yong ;
  • Yun, Min-Seong ;
  • Seong, Dae-Kyoung ;
  • Shin, Hyun-Seok
  • Received : 2010.11.05
  • Accepted : 2011.08.03
  • Published : 2012.03.01


The design of the integrated quench protection (QP) system for the high current superconducting magnet (SCM) has been fabricated and tested for the toroidal field (TF) coil system of the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The QP system is capable of protecting the TF SCM, which consists of 16 identical coils serially connected with a stored energy of 495 MJ at the design operation level at 35.2 kA per turn. Given that the power supply for the TF coils can only ramp up and maintain the coil current, the design of the QP system includes two features. The first is a basic fast discharge function to protect the TF SCM by a dump resistor circuit with a 7 s time constant in case of coil quench event. The second is a slow discharge function with a time constant of 360 s for a daily TF discharge or for a stop demand from the tokamak control system. The QP system has been successfully tested up to 40 kA with a short circuit and up to 34 kA with TF SCM in the second campaign of KSTAR. This paper describes the characteristics of the TF QP systems and test results of the plasma experiment of KSTAR in 2009.




  1. G.S. Lee, J. Kim, S.M. Hwang, C.S. Chang, H.Y. Chang, M.H. Cho, The design of KSTAR tokamak, Fusion Eng. Des. 46 (1999) 405-411.
  2. Kukhee Kim, Mikyung Park, Sang-Hee Hahn,Myungkyu Kim, Jaesic Hong, Sulhee Baek et al., "Development and commissioning results of the KSTAR discharge control system", Fusion Eng. Des.(2008), doi:10.1016/j.fusengdes. 2008.11.005.
  3. Sang-hee Hahn, M.L. Walker, Kukhee Kim, H.S. Ahn, B.G. Penaflor, D.A. Piglowski et. al., Plasma Control System for "Day-one" Operation of KSTAR Tokamak, Fusion Engineering and Design, doi: 10.1016/j.fusengdes.2008.12.082.
  4. Yeong-Kook Oh,W.C. Kim, K.R. Park, M.K. Park, H.L. Yang, Y.S. Kim et al., "Commissioning and initial operation of KSTAR superconducting tokamak", Fusion Eng. Des. (2009), doi:10.1016/j.fusengdes.2008.12.099.
  5. Jae-hoon Choi, et al. "Overview of Superconducting Magnet Power Supply system for the KSTAR 1 st Plasma Experiment", Nuclear Engineering and Technology, Vol.40, No.6, October 2008.

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