A Bus-Voltage-Adaptive Dual-Mode Stacked Half-Bridge LCLC Converter for Electric Vehicles Energy Router Applications

High-voltage Electric Vehicle (EV) battery platforms challenge fast charging compatibility. High-voltage electric vehicle (EV) battery platforms face challenges in fast-charging compatibility. A dual-battery pack scheme utilizing a double-pole double-throw (DPDT) switch improves charging compatibility, but results in an excessively wide bus voltage. Conventional auxiliary power modules (APMs) become unsuitable under such conditions. This paper therefore proposes an adaptive dual-mode buck/boost converter for HV/LV platforms. Firstly, by altering its connection configuration, the proposed converter is better suited for dual-battery-pack systems utilizing DPDT switches. It can accommodate a wide bus voltage range from 250 V to 1000 V (or even higher), while the maximum voltage stress on its MOSFET is only 500 V. Secondly, in boost mode at both platforms, the converter is fundamentally reconfigured into an LLC converter with a parallel LC branch on the primary side (LCLC converter). The magnetizing inductance of this converter increases with the switching frequency, enabling the required voltage gain while simultaneously suppressing circulating current losses. Thirdly, in buck mode at both platforms, it operates as an LLC converter with a larger resonant inductance and higher quality factor, thereby enhancing step-down capability within a narrower frequency variation range. Finally, A 2.4kW prototype with 96% peak efficiency (250-1000V input, 48V output) validates the design performance.