【摘要】 针对二次型Buck变换器开关管电压应力大、效率低的问题,提出了一种新型低应力降压变换器。该变换器在二次型Buck变换器的基础上,通过增加谐振电感、二极管和电容元件得到。理论分析表明,与二次型Buck变换器相比较,在降压特性变化不大的情况下,新型变换器的开关管和部分二极管的电压应力变小;增加的谐振电感使第二级实现了开关管的零电流关断(ZCS),减小了开关损耗,提高了开关管的工作频率,有利于变换器的重量和尺寸的减小;同时,与谐振电感串联的二极管能实现ZCS,减小了二极管的反向恢复损耗。这些优点有利于器件的选择和效率的提高。最后,通过实验验证了理论分析的正确性。更多还原

【Abstract】 Aiming at the problem of high voltage stress on switch and low efficiency of quadratic Buck converter,a new low-stress step-down converter is proposed.Based on the quadratic Buck converter,a resonant inductor,a diode and a capacitor is added into new converter.Theoretical analysis are presented,compared with the quadratic Buck converter,the voltage stress of the switch and partial diodes is reduced with little change on the conversion ratio.By adding a resonant inductance,the zero current switching off(ZCS) of the switching is realized in the second stage and reduces the switching loss,which improves the operating frequency of the switching and helpful to reduce the weight and size of the converter.At the same time,the diode in series with resonant inductors realize ZCS,alleviates the reverse-recovery losses of the diodes.These advantages make component selection for the proposed converter much easier and the efficiency improved.Finally,the experiment is built to verify the theoretical analysis.更多还原