Quasi-static Characteristics in Radial Direction of 100 kWh Class Superconductor Bearing

100 kWh급 초전도 베어링의 지름방향 준정적 특성

  • Jung, S.Y. (Korea Electric Power Research Institute) ;
  • Park, B.J. (Korea Electric Power Research Institute) ;
  • Han, Y.H. (Korea Electric Power Research Institute) ;
  • Park, B.C. (Korea Electric Power Research Institute) ;
  • Lee, J.P. (Korea Electric Power Research Institute) ;
  • Han, S.C. (Korea Electric Power Research Institute)
  • Received : 2010.08.27
  • Accepted : 2010.09.27
  • Published : 2010.10.31

Abstract

A superconductor flywheel energy storage system (SFES) is an electro-mechanical battery which transforms electrical energy into mechanical energy for storage, and vice versa. Many aspects of the quasi-static behavior of flywheel rotors still need to be studied closely, and the rotors require a stable and highly efficient supporting system such as high temperature superconductor (HTS) bearings, which offer dynamic stability without the use of active control. Quasi-static properties of HTS bearings in the radial direction provide data to solve problems which may occur in a running system. Since stiffness in countering rotor vibration is the main parameter for designing an HTS bearing system, we investigated the quasi-static properties of the magnetic force between permanent magnets(PMs) and HTS bulks in the radial direction. We measured radial stiffness, and discovered that bearing stiffness varied greatly depending on the number of active HTS bulks. This is valuable data for predicting the change in stiffness during partial HTS bearing failure. The quasi-static test results are used for optimal design and performance prediction for the 100 kWh class superconductor bearing.

Keywords

References

  1. Y. H. Han, J. R. Hull, S. C. Han, N. H. Jeong, T. H. Sung, and Kwangsoo No, "Design and characteristics of a superconductor bearing" IEEE Tran. Vol. 15, No. 2 (2005).
  2. N. Kosizuka, "R&D of superconducting bearing technologies for flywheel energy storage systems", Physica C 445-448, pp. 1103-1108 (2006). https://doi.org/10.1016/j.physc.2006.05.045
  3. Coombs, T. et al., "Superconducting magnetic bearings for energy storage flywheels", IEEE Trans. Applied Supercon. vol. 9, pp. 968-971 (1999). https://doi.org/10.1109/77.783459
  4. A. C. Day, J. R. Hull et al, "Temperature and frequency effects in a high-performance superconducting bearing", IEEE Trans. On Applied superconductivity, Vol. 13, No. 2, pp. 2179-2184 (2003). https://doi.org/10.1109/TASC.2003.813028
  5. G. Krabbes, G. Fuchs, W.-R. Canders, H. May, R. Palka, High Temperature Superconductor Bulk Materials, WILEY-VCH, pp. 75-104 (2006).
  6. T. H. Sung, S. C. Han, Y. H. Han, J. S. Lee, N. H. Jeong, S. D. Hwang and S. K. Choi, "Design and analysis of flywheel energy storage system using High-Tc superconductor bearings", Cryogenics 42, pp. 357-362 (2002). https://doi.org/10.1016/S0011-2275(02)00057-7
  7. T. Ichihara, K. Matsunaga, M. Kita, I. Hirabayashi et al, "Application of superconducting magnetic bearings to 10 kWh-class flywheel energy storage system", IEEE Trans. on Applied Superconductivity, Vol. 15. No. 2, pp. 2245-2248 (2005). https://doi.org/10.1109/TASC.2005.849622
  8. R. Shiraishi, K. Demachi, M. Uesaka, and R. Takahata, "Numerical and experimental analysis of the rotation speed degradation of superconducting magnetic bearings", IEEE Trans. on Applied Superconductivity, Vol. 13, Nol. 2. pp. 2279-2282 (2003). https://doi.org/10.1109/TASC.2003.813065
  9. I. Masaie, K. Demachi, T. Ichihara and M. Uesaka, "Numerical evaluation of rotational speed degradation in the superconducting magnetic bearing for various superconducting bulk shapes", IEEE Trans. on Applied Superconductivity, Vol. 15, No. 2, pp. 2257-2260 (2005). https://doi.org/10.1109/TASC.2005.849625