BUCK变换器滑模控制研究仿真
Research and Simulation of Sliding Mode Control of BUCK Converter

本文详细讨论了BUCK型降压变换器的滑模变结构控制理论，推导了描述buck变换器的动力学方程，并设计了一种滑模控制(SMC)下的buck变换器。当负载和输入电压在一定程度上发生突变时，该控制器依然能够控制系统使其稳定输出期望电压。此外还提出一种新的方法，采用双闭环控制，即一个内环电流控制和一个外环电压控制。电流环采用滑模控制，电压环采用线性PI控制，并对这两种控制器在负载阶跃变化和输入电压变化情况下进行对比，采用Matlab/Simulink进行仿真，实验结果表明该方法能有效降低Buck变换器的稳态误差，提高其动态响应以及系统的抗干扰能力，增强其对负载突变和输入电压波动的鲁棒性。
This article provides an in-depth discussion of the sliding mode variable structure control theory for buck converters and derives the dynamic equations that describe the behavior of such converters. A novel sliding mode control (SMC) strategy for buck converters is introduced, specifically designed to maintain stable output voltage despite sudden changes in load and input voltage. Moreover, the paper proposes a dual-loop control approach, comprising an inner current control loop and an outer voltage control loop. The current loop utilizes sliding mode control, while the voltage loop employs linear PI (Proportional-Integral) control. The performance of these two control strategies is compared under conditions of load step changes and input voltage variations. Simulations are conducted using Matlab/ Simulink, demonstrating that the proposed method significantly reduces the steady-state error of the buck converter, enhances its dynamic response, and improves the system’s immunity to disturbances, thus increasing its robustness against load surges and input voltage fluctuations.