Journal of Shanghai Jiao Tong University ›› 2025, Vol. 59 ›› Issue (7): 983-994.doi: 10.16183/j.cnki.jsjtu.2023.420

• New Type Power System and the Integrated Energy • Previous Articles     Next Articles

Characteristics of Surface Charge Accumulation on Direct Current GIL Insulators Under Different Dominant Mechanisms Considering Surface Trapping Effect

WANG Yaogang1, WANG Zheming1, LI Ke2, JIA Bowen1, YANG Hua1, YAN Wu3, LU Wu1()   

  1. 1. College of Electrical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
    2. East China Branch of State Grid Co., Ltd., Shanghai 200120, China
    3. State Grid Electric Power Space Technology Co., Ltd., Beijing 102209, China
  • Received:2023-08-25 Revised:2023-09-11 Accepted:2023-09-18 Online:2025-07-28 Published:2025-07-22
  • Contact: LU Wu E-mail:wuluee@shiep.edu.cn

Abstract:

The existing mathematical models for charge accumulation at the gas-solid interface can hardly illustrate some microscopic mechanisms, which need improvement. Therefore, based on the theory of bipolar charge transport at insulating interfaces, a charge transport model is proposed for gas-solid interfaces including the mechanisms of trapping and de-trapping of nonequilibrium carriers, which is incorporated into a three-dimensional simulation model for the charge accumulation on the surface of direct current gas-insulated transmission lines (DC GIL). Numerical simulations of the surface charge accumulation with the dominance of gas-side charge and solid-side charge are conducted, respectively. The simulation results show that in the charge accumulation process dominated by the solid-side charge, halo-like charge and unipolar charge spots appear on the insulator surface. With the increase of energization time, the number of unipolar charge spots increases and the distribution area expands. In the process dominated by gas-side charge, in addition to the appearance of halo-like charge and unipolar charge spots, a pair-distributed bipolar discrete charge speckle occurs at a later stage. Subsequently, the simulation results are analyzed for mechanisms, on the premise that the simulation results are in good contrast with some of the experimental phenomena. The findings of this study can deepen the understanding of the impact of surface trapping effects on charge accumulation behavior.

Key words: direct current gas-insulated transmission lines (DC GIL), simulation studies, surface charge, charge accumulation pattern, surface trap

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