Spatiotemporal Impact of Metro Rail Insulation Degradation on Line Electrical Quantities

Since the traditional method for locating insulation defects in DC traction systems is affected by train operation conditions and leakage point coupling, this paper establishes a three-dimensional rail-ground network model for the study. The model includes the track, discharge network, and through ground, and is constructed using the MALZ module of the CDEGS simulation platform. The study then simulates the distribution characteristics of electrical quantities under various leakage scenarios with moving train loads. The study reveals a strong correlation between the location of the leakage point and the position of the leakage current spike. Additionally, the railthrough ground potential and stray current at the monitoring point are significantly influenced by various train operating conditions. By analyzing the temporal and spatial distribution of rail leakage current amplitudes and the changing characteristics of the potential difference between the rail and discharge network, the influence mechanism of the leakage point on the system’s electrical characteristics is further revealed. The research findings provide a theoretical basis for the precise location of leakage points and lay the foundation for enhancing the safety and reliability of the metro power supply system.