有损LC滤波器和Buck变换器级联系统有源阻尼控制方法

Active damping control method of cascade system for lossy LC filter and Buck converter

以LC滤波器和Buck变换器带恒定负载构成的级联系统,若前级电路LC滤波器参数设计不当,系统会因前后级参数不匹配引发电压振荡。尽管现有研究针对该系统探究了其近似线性化建模、阻抗比判据及阻尼控制设计,但均忽略了滤波器自身损耗的影响。因此,提出了计及滤波器损耗参数的系统电路模型,在此基础上列写小信号方程推导出系统端口等效阻抗,以赫尔维茨劳斯判据分析了其损耗参数对系统稳定性的作用规律,逐一设计了系统有源阻尼前馈控制回路传递函数。最后,分别通过阻抗比判据等效阻抗伯德图及仿真,分析和验证了该控制方法的有效性。

In a cascaded system consisting of LC filters and Buck converters with constant loads,improper design of the front-end circuit′s LC filter parameters can lead to voltage oscillations due to parameter mismatches between stages.Although existing research has explored approximate linearization modeling,impedance ratio criteria,and damping control design of the system,they have overlooked the impact of filter losses.So this paper proposes a system circuit model that includes filter loss parameters.Based on this model,small-signal equations are formulated to derive the equivalent impedance of the system port.Subsequently,the Routh-Hurwitz Criterion is applied to analyze the influence of loss parameters on system stability,leading to the design of individual transfer functions for the system′s active damping feedforward control loop.Finally,the effectiveness of this control method is evaluated and validated through impedance ratio criterion,equivalent impedance Bode plots,and simulation results.