Wide-Band Harmonic Interaction and Characteristic Analysis of Flexible Cooperative Traction Power Supply System

Integrating renewable energy systems (RES) and hybrid energy storage systems (HESS) into railway traction power supply systems represents a critical pathway toward low-carbon and sustainable railway transportation as it enables the utilization of clean energy and enhances energy efficiency. However, this integration introduces new harmonic resonance challenges that require systematic analysis. To quantitatively analyze these harmonic resonance issues, this paper studies a flexible cooperative traction power supply system (FCTPSS) integrated with RES and HESS. Based on harmonic transmission theory, mathematical models of harmonic transmission for both the traction power supply system (TPSS) and the FCTPSS are established. Simulation models of the TPSS and FCTPSS are developed in MATLAB2021b/Simulink. Using these simulation models, the harmonic transmission characteristics of the TPSS and FCTPSS are compared and analyzed. The results indicate that the position of the locomotive and the access position of RES and HESS influence the harmonic transmission characteristics. Importantly, integrating RES and HESS shifts the resonant frequency to higher orders and effectively alleviates resonance issues, thereby improving power quality and supporting the reliable operation of sustainable railway systems. These findings offer valuable design guidance for incorporating RES and HESS into traction power supply systems to facilitate the transition toward greener and more sustainable rail transportation.