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投稿时间：2022-01-09 修订日期：2022-10-31
投稿时间：2022-01-09 修订日期：2022-10-31
中文摘要: 针对传统PI控制的Buck变换器暂态性能差的缺点，本文提出一种基于状态反馈精确线性化的微分平坦控制方法。首先，根据状态空间平均法，建立了电感电流连续导电模式Buck变换器的仿射非线性模型，在此基础上，应用状态反馈精确线性化的方法，推导出状态反馈控制率，实现了系统的能控线性化。其次，针对此状态反馈精确线性化模型，设计了系统前馈控制器；并且将扰动观测器嵌入前馈控制器中，实现对输出电流的补偿；同时，为了消除实际系统由于未建模部分及外部干扰而导致系统实际输出与期望输出之间存在的偏差，设计了误差反馈补偿器。结合前馈控制器与反馈补偿器可得到本文提出的基于状态反馈精确线性化的微分平坦控制，其中，前馈控制器中的微分项保证了变换器系统的快速性，反馈补偿器中的误差项保证了变换器系统的准确性。基于闭环系统的雅可比矩阵，采用特征值灵敏度理论，研究了变换器电路参数变化时对系统特征值的影响程度及趋势，指出减小电感量、增大电容值有利于提高系统的稳定性。最后，搭建了Buck变换器实验样机。实验结果表明，与传统PI控制方法相比较，本文提出的基于状态反馈精确线性化的微分平坦控制方法能更好地抑制输入电压和输出电流的扰动，具有更小的调节时间和超调电压，表现出更优越的暂态性能，该控制策略具有一定的工程应用价值。
Abstract:In this paper, a differential flat control method based on the exact linearization of state feedback was proposed to improve the poor transient performance of the conventional PI controlled Buck converter. Firstly, based on the state space averaging method, an affine nonlinear model of the Buck converter with inductive current continuous conduction mode was established. Based on this model, the state feedback control rate was derived by using the state feedback exact linearization method, and the controllable linearization of the system was realized. Secondly, a feedforward controller was designed for the exact linearized model of the state feedback; and then, a disturbance observer was embedded in the feedforward controller to compensate the output current. Meanwhile, an error feedback compensator was designed to eliminate the deviation between the actual output and the desired output of the system caused by the unmodeled part and external disturbance of the actual system. Combining the feedforward controller and the feedback compensator, a differential flat control method based on the exact linearization of state feedback was proposed. The rapidly and accuracy of the Buck converter system can be respectively guaranteed by the differential term in the feedforward controller and the error term in the feedback compensator. Besides, based on the Jacobian matrix of the closed-loop system, the eigenvalue sensitivity theory was used to study the influence of converter circuit parameter changes on system eigenvalue. The study results show that reducing the inductance and increasing the capacitance is beneficial to improve the stability of the system. Finally, the experimental prototype of the Buck converter was built. The experimental results show that, compared with the traditional PI control method, the proposed differential flat control method based on accurate linearization of state feedback can better suppress the disturbances of input voltage and output current, has less regulation time and overshoot voltage, and shows better transient performance. Consequently, the proposed control strategy has certain engineering application value.
keywords: Buck converter state feedback exact linearization disturbance observer differential flat control sensitivity
文章编号：202200025 中图分类号：TM46 文献标志码：
基金项目:国家自然科学基金项目（51777167）；陕西省教育厅科研计划项目（21JK0567）
| 作者 | 单位 | |
| 皇金锋 | 陕西理工大学 电气工程学院，陕西 汉中 723001 | jfhuang2000@163.com |
| 李慧慧 | 陕西理工大学 电气工程学院，陕西 汉中 723001 | lihuihui9100@126.com |
| 谢锋 | 国网西安供电公司，陕西 西安 710032 |
作者简介:第一作者：皇金锋(1978-),男,教授,博士.研究方向:开关变换器分析与设计.E-mail:jfhuang2000@163.com;通信作者：李慧慧,E-mail:lihuihui9100@126.com
引用文本：
皇金锋,李慧慧,谢锋.基于状态反馈精确线性化Buck变换器的微分平坦控制[J].工程科学与技术,2022,54(6):248-257.
HUANG Jinfeng,LI Huihui,XIE Feng.Differential Flattening Control of Buck Converter Based on State Feedback Exact Linearization[J].Advanced Engineering Sciences,2022,54(6):248-257.
引用文本：
皇金锋,李慧慧,谢锋.基于状态反馈精确线性化Buck变换器的微分平坦控制[J].工程科学与技术,2022,54(6):248-257.
HUANG Jinfeng,LI Huihui,XIE Feng.Differential Flattening Control of Buck Converter Based on State Feedback Exact Linearization[J].Advanced Engineering Sciences,2022,54(6):248-257.