基于ESO的Buck型变换器趋近律控制

A Novel Reaching Law Control for Buck Converter Based on ESO

摘要:

针对Buck型变换器系统中存在的时变干扰，如输出负载波动，本文提出一种基于扩张状态观测器(ESO)的趋近律控制方法。首先，对系统中存在的时变干扰进行建模，把抑制时变干扰问题转换为抑制匹配和非匹配扰动问题。其次，设计一种扩张状态观测器，用于估计匹配和非匹配扰动。然后，根据提出的新型指数幂次趋近律设计滑模控制器，结合ESO，有效抑制时变干扰对系统的影响，并通过Lyapunov稳定性定理分析观测器的收敛性和闭环控制系统的稳定性。最后，仿真结果验证了所提方法的有效性。

Abstract:

In this paper, a new reaching law control method based on extended state observer (ESO) is proposed for buck converter system with time-varying disturbances, such as output load fluctuation. Firstly, the time-varying disturbances in the system are modeled, and the problem of suppressing time-varying disturbances is transformed into the problem of suppressing matched and unmatched disturbances. Secondly, ESO is designed to estimate the matched and unmatched disturbances. Combining with ESO, a new exponential power reaching law sliding mode controller is also designed to suppress the influence of time-varying disturbances for the system effectively. Then, the convergence of observer and the stability of closed-loop control system are analyzed by Lyapunov stability theorem. Finally, the simulation results verify the effectiveness of the proposed method.