When an overhead conductor experiences strand breakage

the corresponding AC resistance increases

leading to the formation of local hotspots in the transmission line

which can adversely affect the safety of power transmission.Existing models for calculating the AC resistance of conductors are primarily developed for conductors without damage.To accurately assess the impact of strand breakage-induced heating on the operation of transmission lines

it is essential to establish a model that considers strand breakage damage.This study focuses on the LGJ-120 conductor and proposes a polynomial model for the resistance of conductors with strand breakage based on AC resistance measurements.The polynomial coefficients are estimated using the least squares method.A comparison between the calculated results and experimental data indicates that the proposed model exhibits high accuracy and can effectively reflect the variations in AC resistance with changes in conductor temperature and current under different degrees of strand breakage.