Buck变换器的降阶扩张状态观测器与无抖振滑模控制（英文）

Chattering free sliding mode control based on reduce order extended state observer method for a DC–DC Buck converter system

中文关键词  Buck变换器  滑模控制  降阶扩张状态观测器  跟踪误差状态空间模型  无抖振

英文关键词  Buck converter  sliding mode control  reduce-order extended state observer  tracking error state space model  chattering free

中文摘要

      针对脉宽调制型Buck变换器的内外干扰和滑模控制的抖振等问题, 本文提出了一种基于降阶扩张状态观测器 和无抖振滑模的新型控制策略. 首先, 建立新型的跟踪误差状态空间模型, 将匹配和不匹配干扰定义为统一的匹配干扰; 然后, 设计降阶扩张状态观测器提高跟踪误差微分和系统干扰的估计速度, 并抵消负载和输入端的电压变化、系统参数 不确定性对控制系统的影响; 其次, 利用跟踪误差微分的估计值设计滑模控制器抑制干扰估计误差, 使得切换项近似为 零, 实现滑模技术的无抖振控制, 提高Buck变换器系统电压跟踪的快速性和准确性. 利用李雅普诺夫稳定判据从理论上 证明了所提控制器的闭环稳定性. 最后, 仿真结果表明所提方法通过抑制抖振和内外干扰有效改善Buck变换器的鲁棒 性和动态性能.

英文摘要

      A novel chattering free sliding mode control (SMC) based on a reduced-order extended state observer (RESO) is proposed for a pulse width modulation based DC–DC buck converter with total disturbances and chattering. First, a novel tracking error state space model is introduced to define the matched and mismatched disturbances as a uniform matched disturbance. Second, a RESO is designed to improve estimation rapidity of tracking error differentiation and system disturbances. Moreover, the influence of load mutation, input voltage variation and system parameter uncertainties can further be attenuated by RESO via a feedforward channel. Third, an estimation of tracking error differentiation based sliding mode controller is designed to attenuate the disturbance estimation error, since the rapidity and accuracy of the buck converter voltage tracking can be improved due to achievement of the chattering free by defining the switching gain of sliding mode controller as zero. In addition, Lyapnuov stability criterion is developed to prove the stability of the proposed closed-loop controller. Finally, the simulation results show that the proposed method can effectively improve the robustness and dynamic performance of Buck converter by attenuating the chattering and total disturbances.