Digital transformation toward new-type power systems has driven the intelligent and miniaturized development of electric power measuring equipment. When embedded in primary high-voltage devices as intelligent components

this equipment faces new electromagnetic compatibility (EMC) challenges. Strong electromagnetic interference (EMI) sources

particularly very fast transient overvoltage (VFTO)

possess strong coupling capabilities

and their high-frequency components (1~30 MHz) readily induce electromagnetic resonance in equipment

significantly impact weak electronic components

and potentially endanger the stable operation of equipment and even the entire system. Conventional peak-suppression protection methods show limited effectiveness against these high-frequency components. To address this issue

this paper develops a model to characterize the propagation

attenuation

and reflection of VFTO step-waves. This model reveals how distributed resistance in gas insulated switchgear (GIS) busbars suppresses EMI

leading to the proposal of a high-resistance coating busbar. This design applies a coating with high magnetic permeability and low electrical conductivity to the busbar surface

increasing resistance without changing the main busbar structure. On this basis

the key factors influencing the busbar’s distributed resistance are analyzed

and a systematic design scheme for the high-resistance coating busbar is subsequently proposed. Field simulations are conducted to verify its insulation performance and current-carrying capacity. Finally

high-resistance coating busbar samples are fabricated and subjected to equivalent tests. The results indicate that the application of the coated busbar reduces the cumulative root-mean-square value of EMI in the 1~30 MHz range by 22.66%

thereby validating the effectiveness of the proposed method in suppressing high-frequency components of strong EMI

and ensuring reliable operation of intelligent measuring equipment.