Shielding of the total electric field above building platforms near UHVDC transmission lines by grounded metal mesh

With the advancement of China’s ultra-high voltage (UHV) projects, the proximity of transmission lines to buildings has intensified grid-environment conflicts, increasing the risk of electric shock from induced electric fields on areas like balconies and building platforms. This study addresses the mitigation of DC total electric field (TEF) on flat-roofed building platforms near UHV direct current (UHVDC) lines by proposing a shielding method using a grounded metal mesh (GMM). A 3D finite-element model integrating buildings, GMMs, and UHVDC lines was developed to analyze the shielding effect on the TEF, which combines electrostatic and space charge excitation fields. The influence of GMM parameters and installation methods was investigated. The method was validated in the 1951 to 1952 section of the ± 800 kV Lingzhou-Shaoxing UHVDC project. Results show that installation parallel to the platform provides superior shielding compared to perpendicular installation, controlling TEF E80 values at 3.95 kV/m and 7.70 kV/m with shielding efficiencies of 16.59 dB and 10.13 dB, respectively, both of which were much lower than the limit of 15 kV/m stipulated in GB 39220-2020 and 20 kV/m stipulated in IEEE Std C95.1-2019. This research offers practical guidance for building protection along DC lines, enabling controllable electric field environments, mitigating grid-residence conflicts, and promoting harmonious coexistence between power facilities and buildings.