Leakage Current Modeling for Grounding in Single-Track Electric Mass Transit Systems

This study utilizes MATLAB/Simulink to analyze leakage current in the DC electric train power supply system. The objective is to develop simulation models using MATLAB/Simulink to evaluate and compare the simulation results with mathematical and discrete models. The study focuses on three simulation models with a drainage diode: FNRCS, SCCNS, and SCCNS. It examines leakage current behavior and assesses rail voltage characteristics over a distance of 0 to 5.00 km. The simulation results for the FNRCS model indicated a voltage drop from 169.90 V at the initial point to -297.38 V at 5.00 km, along with an increase in leakage current to 14.82 A. These findings align with both the discrete and mathematical models. Compared to the mathematical model, the average increase in leakage current was 40.07%. The simulation results for the SCCNS exhibited behavior similar to that of the FNRCS in terms of both rail voltage and leakage current. The average rail voltage of the SCCNS with a drainage diode was 284.62 V, demonstrating a steady decline. However, the leakage current increased significantly with distance. Compared to the SCCNS, SCCNS with a drainage diode exhibited higher rail voltage in the 0-3.00 km range and lower rail voltage in the 3.00-5.00 km range. The development of MATLAB/Simulink models for the railway power supply system has proven to be a practical approach for analyzing rail voltage and leakage current, offering valuable insights compared to discrete and mathematical models.