峰值-谷值电流控制Buck变换器输出电容对称时间常数研究

Study on symmetrical time constant of output capacitance of peak and valley current-mode controlled Buck converter

峰值-谷值电流控制Buck变换器在自身参数变化时对系统稳定性的影响具有对称性。以Buck变换器为例,建立了峰值-谷值电流控制的对称分段线性模型,推导了对应的Jacobi矩阵,基于此,推导了系统由稳定工作状态过渡到不稳定工作状态时输出电容时间常数的对称临界值。最后通过在PSIM软件中搭建仿真电路进行实验验证,研究结果表明,峰值-谷值电流控制Buck变换器在参数变化时,系统的工作状态存在对称性,同时所提出的输出电容时间常数临界值对于系统参数设计及其器件选择具有十分重要的指导作用。

The peak-to-valley current control Buck converter has symmetry for the influence on the stability of the system when its own parameters change.Taking the Buck converter as an example,a symmetric piecewise linear model of peak-to-valley current control is established,and the corresponding Jacobi matrix is derived.Based on this,the symmetrical threshold of the output capacitor time constant is derived when the system is in stable state transition to unstable operation.Finally,the experimental results are verified by constructing the simulation circuit in PSIM software,the results show that the peak-to-valley current control Buck converter has symmetry in the working state of the system when the parameters change,and the output capacitor time constant threshold value proposed is very important for the system parameter design and device selection.