Dynamic interaction and energy redistribution in shared DC-link multi-output CC–CV flyback converters fed by an MPC-controlled boost PFC

Abstract

Abstract Multi-output Constant Current–Constant Voltage (CC–CV) power conversion systems are increasingly employed in battery charging applications because they enable multiple charging channels to operate from a common Direct Current (DC)-link. However, the dynamic interaction and energy redistribution occurring through the shared DC-link under different charging conditions remain insufficiently investigated. This paper presents a multi-output CC–CV power conversion system supplied by a Model Predictive Control (MPC)-controlled Boost Power Factor Correction (PFC) front-end to investigate the interaction mechanism under synchronous and asynchronous operating conditions. A theoretical framework based on energy conservation and DC-link power balance is developed to explain the coupled behaviour among multiple charging channels. The proposed model is validated through detailed MATLAB/Simulink investigations using two parallel flyback converters operating under independent CC–CV regulation. The results demonstrate stable grid-side operation with near-unity power factor and regulated DC-link voltage while confirming that asynchronous mode mismatch significantly affects input current, transient energy redistribution, and overall conversion efficiency. The highest efficiency of 91.60% is obtained under the Transition–Constant Current (T–CC) operating condition, whereas the lowest efficiency of 88.94% occurs during the Constant Voltage–Constant Current (CV–CC) condition. The proposed framework provides valuable insight into the analysis and design of shared DC-link multi-output power conversion systems for battery charging and other distributed DC energy applications.