Nuclear Techniques ›› 2017, Vol. 40 ›› Issue (7): 70402-070402.doi: 10.11889/j.0253-3219.2017.hjs.40.070402


Research on the technology of series-connected IGBTs in EAST-NBI suppressor grid power supply

ZHANG Yabing1,2, LIU Zhimin1,2, JIANG Caichao1, LIU Sheng1, CHEN Shiyong1, PAN Junjun1, HU Chundong1   

  1. 1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China;
    2. University of Science and Technology of China, Hefei 230026, China
  • Received:2017-01-11 Revised:2017-05-08 Online:2017-07-10 Published:2017-07-10
  • About author:10.11889/j.0253-3219.2017.hjs.40.070402
  • Supported by:
    Supported by Foundation of Institute of Plasma Physics, Chinese Academy of Sciences (No.DSJJ-15-GC03)

Abstract: Background: Neutral beam injector (NBI) is one of the important parts of experimental advanced superconducting tokamak (EAST) for auxiliary heating. Four grids structure, including accelerator grid, gradient grid, suppressor grid and ground grid, is adopted in extraction system of NBI ion source. The suppressor grid power supply is high voltage DC power supply to offer negative potential to suppressor grid. To meet the requirements of output characteristics of suppressor grid power supply, series-connected insulated gate bipolar transistor (IGBT) is used as modulation switch in output port. Purpose: This work aims to research the influence of the technology of series-connected IGBTs to voltage balancing effect and output characteristics of suppressor grid power supply. Methods: In this paper, IGBT switch is modeled and simulated at different parameters with PSpice software. Results: The simulation results show that, under certain conditions, the value of capacitance in resistance capacitance diode (RCD) snubber circuit has a crucial influence on the effect of dynamic voltage balancing and the turn-off characteristics of power supply, and the value of resistance determines the discharge time and the peak discharge current of capacitance. Finally, the corresponding test result is presented. Conclusion: This research can identify the quantitative relationship between parameters of snubber circuit and effect of voltage balancing, as well as output characteristics of suppressor grid power supply. So that, it can guide the optimization of suppressor grid power supply with simulation data, which is meaningful for the security and stability of NBI ion source operation.

Key words: Suppressor grid power supply, Series connected IGBTs, PSpice, RCD, Voltage balancing

CLC Number: 

  • TL67