A Bidirectional Multidevice Interleaved SEPIC–ZETA DC–DC Converter for High-Efficiency Electric Mobility

This paper presents a high-efficiency bidirectional multidevice interleaved SEPIC–ZETA DC–DC converter for electric mobility applications. The proposed converter offers key advantages, including reduced current and voltage ripple at both the input and output ports, achieved through a port ripple frequency six times higher than the switching frequency. Additionally, the required magnetic and capacitor volume is significantly reduced due to an inductor ripple frequency twice the switching frequency, leading to minimized power losses, reduced stress on power components, and enhanced efficiency. The use of a multidevice structure facilitates more efficient inductor volume optimization and provides improved fault redundancy. The converter is particularly suited for electric vehicle energy management systems, enabling efficient energy management among the various subsystems. It operates in open-loop mode, and this manuscript details the steady-state operating principle under continuous conduction mode. Design guidelines for parameter selection, comprehensive mathematical derivations, and a comparative analysis with existing DC-DC converters are presented. To validate the proposed topology, a 5 kW laboratory prototype was developed and tested across a wide range of load conditions. The experimental results confirm the converter’s high performance, achieving a peak efficiency of 98.6% at rated power.