Objective The application scheme of reinforced insulating coating for rails is investigated to address the stray current issues and optimize the scope of above coating. Based on stray current control indicators, the implementation range of the reinforced insulating coating for rails centered on traction substations, is optimized.

Method A field-circuit coupling model based on the boundary element method is used to calculate the rail leakage current and the earth potential gradient around the railway line. Centered on traction substations, an iterative search algorithm is employed to determine the implementation distance of the reinforced insulating coating for rails. Using stray current control indicators as the evaluation criterion and traction substations as the center for applying the reinforced insulating coating, the above-mentioned implementation distance is calculated through the iterative search algorithm.

Result & Conclusion  The case analysis shows that with the proposed optimization algorithm, when the rail transition resistance is increased to 30 Ω·km, the average positive leakage current of the entire line is less than 2.5 mA/m, and the earth potential gradient at 50 m from the line is less than 2.5 mV/m. Compared to applying the reinforced insulating coating to the entire line, this approach reduces the scope of the mentioned coating by 63.8%.