基于状态反馈精确线性化Buck变换器的微分平坦控制

针对Buck变换器由于输入电压和输出电流等外部扰动及电路参数摄动等不确定因素引起系统输出电压变化的问题，提出一种基于状态反馈精确线性化的微分平坦控制方法。根据状态空间平均方程建立了变换器的仿射非线性模型，通过坐标变换推导出状态反馈控制率。在状态反馈精确线性化模型基础上，设计了微分平坦控制器，同时将扰动观测器嵌入控制器中，进一步提高了系统对电路参数摄动和外部扰动等内外干扰的处理能力。最后应用灵敏度理论分析了变换器的稳定性，可知减小电感量、增大电容值有利于提高系统的稳定性。实验结果表明，与传统PI控制方法相比，本文所提控制方法对输入电压和输出电流扰动具有更强鲁棒性，输出电压纹波更小，且系统响应速度能提升近50%。本文研究对DC-DC变换器控制器的设计具有参考意义。

Differential Flattening Control of Buck Converter Based on State Feedback Exact Linearization

This paper proposes a differential flat control method based on the exact linearization of state feedback for the Buck converter due to external disturbances such as input voltage and output current and uncertainties such as circuit parameter uptake, which cause system output voltage variations. The affine nonlinear model of the converter is established according to the state-space averaging equation, and the state feedback control rate is derived by coordinate transformation. Based on the state feedback exact linearization model, a differential flat controller is designed, and a disturbance observer is embedded in the controller to further improve the system''s ability to deal with internal and external disturbances such as circuit parameter uptake and external disturbances. Finally, the sensitivity theory is applied to analyze the stability of the converter, and it is known that reducing the inductance and increasing the capacitance value is beneficial to improve the stability of the system. The experimental results show that compared with the traditional PI control method, the proposed control method is more robust to the input voltage and output current disturbances, the output voltage ripple is smaller, and the system response speed can be improved by nearly 50%. This paper is of reference significance to the design of DC-DC converter controllers.