Abstract:A dynamic distribution modeling method for stray current is proposed to address the problem of insulation damage of rail transit fasteners leading to a decrease in rail to ground transition resistance and a surge in stray current that corrodes buried metal structures. Based on the traction characteristics of the rail transit and the theory of geoelectric field，the dynamic ground potential distribution within the rail transit operating range is calculated. The interference range of stray current during insulation damage of steel rail fasteners is evaluated based on the ground potential distribution and gradient. Based on the Chan algorithm in the TDOA positioning model， a two-step WLS estimation is performed on the time-domain signal of ground potential to locate the point of insulation damage on the steel rail. Finally，the average error and noise resistance of the algorithm under different numbers of ground potential measurement points are analyzed to verify the accuracy of the positioning algorithm.