一种低输入纹波电流的Buck变换器及其控制方法

Buck converter with low input ripple current and its control method

针对电力电子电路中输入电流断续导致的谐波和电磁干扰问题,以Buck变换器为对象,提出了一种输入纹波电流抑制电路。该电路通过一个功率管、两个电容构成了p型混合式滤波结构,在所提控制策略下,功率管被控制为一个恒定直流源,在实现输出电压稳定的同时,有效地抑制了输入侧电流纹波。在介绍该电路工作原理基础上,分析能同时控制功率管和开关管工作的控制策略,给出了设计方法,最后制作了一台输入110 V、输出28 V、负载65 W的实验样机,实验结果验证了电路和控制方法的有效性。

Aiming at the problems of harmonics and electromagnetic interference caused by power electronic circuits with intermittent input current,an input ripple current suppression circuit was proposed,using a Buck converter as the target.The circuit used a power tube and two capacitors to form a hybrid filter structure.Under the proposed control strategy,the power tube was controlled as a constant DC source,which effectively suppressed the input current ripple while achieving stable output voltage.The working principle of the circuit was analyzed in detail,the control strategy that could control both the power tube and the switching tube was introduced and analyzed,and the design method was given.Finally,an experimental prototype with input of 110 V,output of 28 V and load of 65Wwas made.The experimental results verify the effectiveness of the circuit and control method.