Input Voltage Sharing Control Strategy Based on Voltage Uplift Characteristics for ISOP-DAB Converter

In high-power applications, integrating low-voltage DC microgrids into medium-voltage DC distribution networks requires the use of DAB (Dual Active Bridge) converters configured in an input-parallel output-series ISOP-DAB system. Traditionally, modules are interconnected using a voltage-sharing bus. This setup, combined with a basic duty cycle bus, regulates the system's output voltage. It also ensures voltage equalization across all modules. However, failures in these buses can compromise system performance. To address this issue, a control strategy for input voltage sharing in ISOP-DAB system is introduced, leveraging output voltage uplift characteristics in this paper. Initially, the topology of ISOP-DAB converter is analyzed. Subsequently, the operational principles of the output voltage uplift characteristics are detailed. Finally, the effectiveness of the proposed control strategy is validated through experiments involving a system composed of three DAB converter modules.