基于电容ESR和预测调制的DC-DC变换器双环控制策略研究

A Control Strategy Research with Two Loops Based on the Output ESR of the Capacitor for the DC-DC Converter

针对boost型DC-DC变换器,研究基于输出电容ESR纹波电压的预测调制控制策略.首先提出了无需电流采样,并采用输出电容ESR纹波电压的双环控制系统.其次,为了提升DC-DC变换器系统性能,引入了预测调制策略,可以提高变换器瞬态响应速度,减小由输入电压及负载变化引起的扰动.同时,为避免次谐波振荡,采用谷值后缘预测调制技术.最后,对该变换器进行Simulink仿真,结果表明,采用基于输出电容ESR纹波电压的双环控制,结合谷值后缘预测调制技术,可以稳定变换器输出电压,提升瞬态响应性能.该策略无需电流采样以及谐波补偿等模块,能够有效降低硬件成本.

This paper researches a predictive modulation based on the output ripple voltage across of the ESR of the capacitor for the boost DC-DC converter.Firstly,this paper introduces the converter has two voltage feedback loops,which samples the ripple voltage across ESR of capacitor without sampling current.Secondly,in order to improve the digital control performance,the predictive technique is used.With that technique,the converter has faster transient response and perturbation is decreased.And at the same time,to avoid sub-harmonic oscillation,voltage valley trailing-edge modulation is adopted.Finally,boost DC-DC converter is controlled by above techniques and the simulation results made by Simulink show that it has good stability and transient response performance under perturbation.No current sensor or slope compensation needed in the implementation,and the cost of the converter is effectively reduced.