Influence of Conductors on the Dynamic Responses of Reinforced Concrete Pole–Conductor Systems Under Seismic Action

With the expansion of the power system scale and the increasing complexity of distribution network structures, the safety of power facilities has become increasingly prominent under natural disasters, such as earthquakes. As the core support of distribution networks, the seismic performance of reinforced concrete pole–conductor systems directly affects the safe operation of power systems. Compared with single-pole structures, the coupling effect between poles and conductors significantly complicates the mechanical characteristics of the system. This paper focuses on a typical 10 kV distribution line-reinforced concrete pole–conductor system. A refined “three-pole two-conductor” finite element model considering the geometric nonlinearity of conductors is established via ANSYS (Analysis System) software. Through modal analysis and nonlinear dynamic time–history analysis, the natural vibration frequencies, displacement responses of poles, and root stress distribution patterns under different conductor spans (60 m, 80 m, and 100 m) and span-to-height ratios (5–6.7) were systematically investigated. The results indicate that the mass–sag effect of conductors reduces the natural vibration frequency of the pole–conductor system by 10–18%, and its dynamic influence exhibits nonlinear differences as the span increases. When the span-to-height ratio is within the range of 5–6.7, the vibration of conductors significantly amplifies the stress at the pole roots, suggesting that a dynamic amplification factor of up to 1.17 was observed in this study, which can serve as a reference for the seismic design of similar distribution lines.