二次型Buck变换器的分析与设计

二次型Buck变换器因其可以拓宽输入电压范围而得到越来越广泛的关注。首先分析了二次型Buck变换器的工作原理,解析了其工作模态,运用伏秒平衡、电荷平衡推导了连续导电模式CCM(continuous conduction mode)下电压、电流关系表达式,给出了各电路元件的设计公式。根据各功率半导体器件的电压电流波形得到器件应当承受的最大电压和平均电流表达式,从而为器件选型提供依据。最后,根据前面的分析设计制作了一台样机,实验结果表明该样机达到设计要求,且具有良好的抗负载扰动能力。

Analysis and Design of Quadratic Buck Converter

The quadratic Buck converter is attracting more and more attention recently due to its wide range of input voltage. This paper has analyzed the work principle as well as work mode of the quadratic Buck converter. Voltage and current relational expressions are derived by volt-second balance and charge balance when circuit works under Continuous Conduction Mode (CCM), design formulas of the circuit elements are given. According to the voltage and current waveforms of power semiconductor devices, maximum voltage and average current that the devices should withstand are obtained, which provide the basis for device selection. Finally, a prototype is designed and manufactured according to the previous analysis. Experiment shows that the prototype well meets the design requirements and has good anti-load disturbance capability.