Given the impact of the ion flow field

precisely determining the potential of the aboveground wire is essential for the design and safety evaluation of the de-icing device during the non-power-off de-icing procedure of DC transmission lines. Considering the limitations of current methods—which mainly rely on equivalent resistance approximations or optimization techniques to address the suspended potential in ion flow fields—and the lack of clear characterization and mechanistic analysis of steady-state boundary constraints

this paper builds on the distribution characteristics of the steady-state field strength. It specifies the steady-state constraints near the overhead ground wire boundary as “zero ion concentration

a uniformly normal boundary field

and a minimum field value of zero.” An iterative algorithm is then proposed

using the charge accumulation on the suspended conductor as the key variable

so as to establish a self-consistent theoretical and computational framework. The results reveal the near-zero charge region and its shielding effect induced by the synthetic electric field. Comparison with existing experimental data further verifies the accuracy and validity of the method. The proposed technique is utilized to determine the floating potential and charging potential of the overhead ground wire of the DC transmission line under actual operational conditions. The calculation results demonstrate that when solely the inner sub-conductor undergoes corona discharge

the influence of the spatial ion flow field on the suspended potential of the ground wire is comparatively limited; the charging potential of the ground wire exhibits a positive correlation with the grounding resistance value and a negative correlation with the corona discharge field strength of the conductor. The pertinent findings and conclusions may offer theoretical insights for assessing the overhead ground wire potential and electromagnetic environment of DC transmission lines.