输入串联输出串联型软开关BOOST级联拓扑及其控制策略

Topology and Control Strategy for Input-series and Output-series Cascaded Soft-switching BOOST Converter

针对开关电源高电压等级的需求,提出一种输入串联输出串联的软开关BOOST级联变换器拓扑。该拓扑由两个完全一致的BOOST电路输入串联输出串联上下级联构成,其器件电压应力为输出电压的一半,使得开关电源能够利用高性价比的低电压等级功率管;引入ZVT谐振回路,降低开关管损耗,提升系统效率,减小EMI干扰;引入中点电位平衡控制策略,使各器件电压应力保持一致。最后通过仿真与试验样机验证了该拓扑性能的优越性与控制策略的准确性。

To meet the demand of higher voltage for power converters, an input-series and output-series cascaded soft-switching Boost topology was proposed. This topology is composed of two identical Boost converters, which can half the voltage stress of power devices and in which higher cost-effective and lower voltage power devices can be used. Then a ZVT resonant circuit was introduced to reduce the loss of the power devices, improve the efficiency of the converter and lower the EMI. The control strategy for neutral voltage balance was also introduced to strongly keep the half voltage stress for those power devices. Finally, Matlab simulations and experimental prototype were built to verify the novel topology and control strategy.