双管Buck-Boost变换器的带输入电压前馈双闭环控制策略

Dual-loop control with input voltage feedforward for dual-switch Buck-Boost converter

针对宽范围输入的双管Buck-Boost变换器,在Buck和Boost两模式之间进行切换和输入电压发生波动时,电感电流和输出电压存在较大波动的问题,提出了带输入电压前馈的两模式平均电流控制策略。该策略通过将具有电压电流双闭环结构的平均电流控制与单载波-双调制的调制方法相结合,来提高变换器的动态响应性能,实现变换器两模式的自动近似平滑切换,同时对电感电流进行有效控制,保护设备安全。为了克服传统双闭环前馈函数实现和化简困难的缺点,提出将输入电压前馈引入电流内环从而大幅提高了变换器的输入动态响应性能。最后建立了MATLAB/Simulink仿真模型和硬件试验平台,验证了所提控制方法的有效性。

A strategy of two-mode average current control combined with input voltage feedforward is proposed for the wide input-range dual-switch Buck-Boost converter to suppress the big fluctuation of its inductive current and output voltage during the mode switching and when the input voltage fluctuates,which combines the single-carrier dual-modulation method with the average current control in the voltage-current dual close-loop configuration to improve the dynamic response performance of the converter,realize the approximately smooth and automatic switching between Buck and Boost modes,and effectively control the inductive current for the safety of equipments. The input voltage is fed forward to the inner current loop to avoid the troublesome simplification and implementation of feedforward function for traditional dual closeloop control and greatly improve the dynamic response performance of converter input. A MATLAB / Simulink model and a hardware test platform are established to verify the validity of the proposed control strategy.