Integrated Compensation System Based on YNVD Balanced Transformer and Supercapacitor Energy Storage
Abstract
High-speed railway traction power supply systems suffer from power quality issues, including negative sequence, harmonics, and reactive power, as well as low utilization of regenerative braking energy. To address these issues, this paper proposes a collaborative control scheme based on YNVD balanced transformer, railway power conditioner (RPC), and supercapacitor (SC) energy storage. The YNVD transformer serves as the main circuit, the RPC performs power quality compensation and enables energy interaction, and the SC connects to the DC side of the RPC via a bidirectional DC/DC converter. Based on the analysis of the power supply characteristics and RPC compensation mechanism, a multi-condition adaptive energy management strategy is formulated to improve both power quality and regenerative braking energy efficiency. The system operates in five modes to realize adaptive condition matching. A hysteresis control strategy for RPC converters and a current closed-loop cooperative control strategy for DC/DC converters are designed. Matlab/Simulink simulation results verify that the proposed scheme effectively suppresses grid-side negative sequence and harmonic current components, significantly improves power quality, and realizes efficient storage and release of regenerative braking energy, providing a feasible solution for the performance optimization of electrified railway traction power supply systems.