【摘要】 离网型逆变器通常采用多节锂电池串并联供电，存在电池组充放电不均衡问题。针对小功率应用场景，设计了一种以3.2 V磷酸铁锂单电芯为输入的低压逆变器前级升压电路。为克服传统拓扑在高升压比、大电流条件下升压困难与损耗大的问题，提出了一种两级式升压结构：第一级采用两相交错并联同步整流Boost电路将3.2 V升至12 V,第二级采用推挽电路配合全桥整流将12 V升至400 V。完成了硬件设计与实物制作，实验结果表明，该电路可实现3.2 V至400 V的大升压比变换，在逆变器满载100 W输出时效率达80%,具有良好的带载稳定性。更多还原

【Abstract】 Off-grid inverters are usually powered by multiple lithium batteries connected in series-parallel, which leads to cell imbalance during charging and discharging.For low-power applications, this paper presents a front-end boost circuit for a low-voltage inverter with a single 3.2 V LiFePO₄ cell as the input. To address the challenges of conventional topologies in achieving high voltage gain and high current capability simultaneously, a two-stage Boost architecture is proposed: the first stage employs a two-phase interleaved synchronous-rectification Boost circuit to step up the voltage from 3.2 V to 12 V, and the second stage utilizes a push-pull converter with a full-bridge rectifier to further boost it to 400 V. Hardware design and physical implementation are completed. Experimental results demonstrate that the proposed circuit achieves a high voltage conversion ratio from 3.2 V to 400 V, with an efficiency of 80% at the inverter′s full load of 100 W, indicating excellent load stability.更多还原