A comprehensive protection scheme for regenerative braking energy utilization system in electrified railways

Abstract The regenerative braking energy utilization system (RBEUS) stands as a promising technique for improving the efficiency and power quality of electrified railways. Beyond the vital aspects of energy management and control strategies, ensuring fault protection is paramount for the secure and steady operation of the traction power supply system (TPSS) integrated with RBEUS. This paper introduces an innovative protection scheme tailored to diverse RBEUS application scenarios. Firstly, fault categories are streamlined into three levels: system, equipment, and warning. Subsequently, a novel multi-port active power differential protection method, aligned with RBEUS operational principles, is crafted to serve as a comprehensive and sensitive main protection. Building upon this foundation, a hierarchical protection structure for RBEUS is established, addressing the intricacies and variations in fault types while boosting anti-disturbance capabilities under faulty conditions. Embracing the principle of railway-oriented safety, a collaborative RBEUS-TPSS protection scheme is put forth. Finally, through simulated scenarios encompassing various fault conditions, the proposed scheme’s feasibility and effectiveness are convincingly validated.