电流型控制单电感双输出开关变换器稳定性与瞬态特性分析

Stability and Transient Response Analysis of Current-Mode Controlled Single-Inductor Dual-Output Converter

提出一种单电感双输出(SIDO)开关变换器的电流型控制技术。以工作于连续导电模式(CCM)的SIDO Boost变换器为例,详细分析电流型控制CCM SIDO Boost变换器的工作原理、工作时序、系统稳定性,得到变换器稳定工作的条件。建立电流型控制CCM SIDO Boost变换器的时域仿真模型,通过时域仿真分析变换器的稳态性能、瞬态性能、输出支路的交叉影响以及稳定性。研究结果表明:相比于传统的共模-差模电压型控制,电流型控制CCM SIDO Boost变换器可提高变换器的瞬态响应速度并抑制输出支路间的交叉影响;对于变换器存在的不稳定性问题,可以通过引入适当的斜坡补偿解决。最后通过实验验证了理论分析的正确性。

This paper proposes a current-mode control technique of single-inductor dual-output(SIDO)switching converter.Taking SIDO Boost converter in continuous conduction mode(CCM)as an example,its working principle,operation sequence and stability are analyzed,and then the steady-state working condition is obtained.By establishing the time-domain simulation of current-mode controlled CCM SIDO Boost converter,the steady-state performance,transient performance,output crossregulation and stability are analyzed respectively.It is found that,compared to the traditional common-mode and difference-mode voltage-mode controlled SIDO Boost converter,current-mode controlled SIDO Boost converter has improved transient response and reduced output cross-regulation.The instability can be eliminated by using slope compensation.Finally,the validity of the theoretical analysis is proved by hardware experiment.