Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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Study of power diodes used for MRI applications

  • Ajit Nandawadekar (Department of Electrical Engineering, Delhi Technological University) ;
  • Mukhtiar Singh (Inter University Accelerator Centre) ;
  • Soumen Kar (Department of Electrical Engineering, Delhi Technological University)
  • Received : 2023.03.15
  • Accepted : 2023.10.31
  • Published : 2024.02.20
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Abstract

Rectifier diodes play a vital role in the operational aspects of a superconducting magnet, and their selection and characterization are crucial for optimal performance and reliability. These diodes are placed within the magnet cryostat, which subjects them to liquid helium (4.2 K) or cryogenic temperatures. The behavior of power diodes can change significantly at cryogenic temperatures. Hence, it is essential to verify their performance before they are installed onto a superconducting magnet system. Thus, a test bench was developed to determine the V-I characteristics of power diodes at low temperatures. In this paper, the two power diodes were tested at 300 K, 77 K, and 4.2 K. The forward voltage was found to increase and have a modest reduction in the on-resistance with the decreases in temperature. The diodes withstood low temperatures down to 4.2 K. The observed forward voltage for the power diode was 4.78 V at 4.2 K, which is around 6-7 times higher than that at room temperature.

Keywords

Acknowledgement

The authors would like to thank the Cryogenic Group of the Inter-University Accelerator Centre, New Delhi, for their support in providing liquid helium and liquid nitrogen for this experimental study. The authors also like to thank Vijay Soni, Dr. Navneet Kumar, Sankar Ram T., S.K. Saini, Rajesh Kumar and Dr. R.G. Sharma for their technical help in conducting the experiment. The authors would also like to thank SAMEER-Mumbai for their support in carrying out this activity for the IMRI project.

References

  1. Kar, S., Suman, N., Ram, S.T., Soni, V., et al.: Development of high homogeneity and high stability 1.5T superconducting magnet for whole body MRI scanner. Indian J. Cryog. 44, 193-198 (2019) https://doi.org/10.5958/2349-2120.2019.00034.7
  2. Hollis T.J.: Non-coupling magnet shielding coil, US patent 0021465 A1, (2004)
  3. Gabrielse, G., Tan, J., Clateman, P., Orozco, L.A., Rolston, S.L., Tseng, C.H., Tjoelker: A Superconducting solenoid system which cancels fuctuations in the ambient magnetic. Field J. Magn. Reson. 91, 564-572 (1991)
  4. Iwasa, Y.: Case Studies in Superconducting Magnets. Springer, New York (2009)
  5. Yamamoto, S., Yamada, T., Iwamoto, M.: Quench protection of persistent current switches using diodes at cryogenic temperature. Proceedings of the 19th annual IEEE PECS recreation, pp 11-14 (1988)
  6. Chouhan, S., Green, M., Zeller, A.: Voltage characteristics of diodes used for passive quench protection of low-current magnets. IEEE Trans. Appl. Supercond. 25, 1-4 (2015)
  7. Willering, G.P., et al.: Performance of the cold powered cold diodes and diode leads in the main magnets of the LHC. IOP Conf. Ser.: Mater. Sci. Eng. 101, 012076 (2015) https://doi.org/10.1088/1757-899X/101/1/012076
  8. Gui, H., et al.: Review of power electronics components at cryogenic temperatures. IEEE Trans. Power Electron. 35, 5144-5156 (2020) https://doi.org/10.1109/TPEL.2019.2944781
  9. Soni, V., Gupta, A., Kar, S.: High-power cold diodes for the protection of the 1.5 T superconducting MRI magnet system. Semicond. Sci. Technol. (2022). https://doi.org/10.1088/1361-6641/ac7163
  10. Ostapchuk, M., Dmitry, S., Daniil, S., Sergey, Z.: Research of static and dynamic properties of power semiconductor diodes at low and cryogenic temperatures. Inventions 7, 96 (2022)
  11. Rajashekara, K., Akin, B.: A review of cryogenic power electronics - status and applications. In: 2013 International electric mchines & drives conference. Chicago, IL, USA, pp 899-904 (2013). https://doi.org/10.1109/IEMDC.2013.6556204
  12. Ward, R.R., et al.: Power diodes for cryogenic operation. Proc. IEEE 34th Power Electron. Spec. Conf. 4, 1891-1896 (2003)
  13. Yang S.: Cryogenic characteristics of IGBTs. Ph.D. dissertation, Univ. Birmingham, Birmingham, UK, (2005)
  14. Jia C.: Experimental investigation of semiconductor losses in cryogenic DC-DC converters. Ph.D. dissertation, Univ. Birmingham, Birmingham, UK, (2008)
  15. Nandawadekar, A., Kar, S., et al.: Thermal and electrical behaviour of the persistent current switch for a whole-body superconducting MRI magnet. IEEE Trans. Appl. Supercond. (2021). https://doi.org/10.1109/TASC.2021.3076748
  16. Standard Recover Diode, Vishay, www.vishay.com, 2020 [Online]. https://docs.rs-online.com/39f1/0900766b8130080d.pdf. Accessed 11 May 2020.
  17. Ultra-Fast Avalanche Sinterglass Diode, Vishay, www.vishay.com, 2020 [Online]. https://www.vishay.com/docs/86044/byv2850.pdf. Accessed 11 May 2020.
  18. Bose, B.K.: Power electronics and AC. Drives, Prentince-Hall, Englewood, NJ (1986)