一种新型数字控制SIDO Buck变换器仿真研究

Simulation of Novel Digital Controlled Single-Inductor Dual-Output Buck Converter

分析了工作于电感电流连续导电模式(Continuous Conduction Mode,CCM)单电感双输出(Single-Inductor Dual-Output,SIDO)buck变换器的主电路结构及其工作原理。建立了SIDO buck变换器的输出电流与开关管导通占空比的牛顿迭代关系。提出了基于输出电流反馈的数字谷值电压控制SIDO buck变换器,采用VC++和PSIM联合仿真,对基于输出电流反馈的数字谷值电压控制SIDO buck变换器和传统差模电压-共模电压控制SIDO buck变换器进行了仿真研究与比较分析。研究结果表明:基于输出电流反馈的数字谷值电压控制方法不但具有差模电压-共模电压控制方法无输出支路间交叉影响的特点,而且减小了开关变换器的纹波、提高了开关变换器的启动快速性和响应速度,改善了系统的稳态性能和瞬态性能。

The circuit structure and operation principle of single-inductor dual-output （SIDO） buck converter operating in continuous conduction mode （CCM） was analyzed. The Newton iteration duty ratio expression of SIDO buck converter was established. Then the digital valley voltage control of SIDO buck converter based on output current feedback was proposed and studied, compared with traditional different-mode voltage and common-mode voltage control of SIDO buck converter through the co-simulation method of VC＋＋ and PSIM software, digital valley voltage control of SIDO buck converter based on output current feedback not only eliminated crossing regulation between two outputs as same as the traditional one, but also reduced output voltage ripple and improves response speed of the switch converter, i.e. improved both steady-state performance and transient performance of the system.