基于平坦理论的三相交错并联双向DC-DC变换器改进型高阶滑模控制  

High Order Sliding Mode Control of Three-phase Staggered Parallel Bidirectional DC-DC Converter Based on Flat Theory

作　　者：皇金锋[1] 陈旭 李聪林 HUANG Jinfeng;CHEN Xu;LI Conglin(School of Electrical Engineering Shaanxi University of Technology,Hanzhong 723001,China)

机构地区：[1]陕西理工大学电气工程学院,陕西汉中723001

出　　处：《湖南大学学报(自然科学版)》2025年第2期164-175,共12页Journal of Hunan University:Natural Sciences

基　　金：陕西省自然科学基金资助项目(2023-JC-YB-442)。

摘　　要：针对直流微电网中储能系统功率波动、负载侧负荷频繁投切等不确定因素引起母线电压产生波动的问题,以储能系统中三相交错并联双向DC-DC变换器为研究对象,提出一种基于级联有限时间扩张状态观测器(cascade finite-time extended state observer,CFT-ESO)的微分平坦和改进型超螺旋滑模双闭环复合控制策略.首先,建立三相交错并联双向DC-DC变换器的数学模型,并根据微分平坦理论将其直流系统转化为微分平坦系统,结合两级具有快速收敛性的有限时间扩张状态观测器提高对系统集总扰动的估计精度.其次,采用内环微分平坦控制、外环改进型超螺旋滑模控制的双闭环控制系统,既能提高系统动态响应过程,又能利用高阶滑模控制算法抑制抖振,同时解决变换器升压模式中非最小相位问题.再次,通过Lyapunov理论证明控制系统的稳定性.最后,利用MATLAB/Simulink仿真软件以及搭建实验平台对控制策略进行验证,结果表明,本文所提控制策略能够很好地抵抗扰动,提高系统的暂态性能.This paper addresses the issue of bus voltage fluctuations caused by uncertain factors,such as power fluctuations in distributed photovoltaic systems and frequent switching of loads in direct current(DC)microgrids.The study focuses on a three-phase interleaved parallel bidirectional DC-DC converter in the energy storage unit of the microgrid and proposes a differential flatness-based and improved super-twisting sliding mode dual closed-loop composite control strategy based on a cascade finite-time extended state observer(CFT-ESO).Firstly,a mathematical model of the three-phase interleaved parallel bidirectional DC-DC converter is established.The DC system is transformed into a differentially flat system based on the theory of differential flatness.The estimation accuracy of the system’s total disturbance is improved by combining a two-level finite-time extended state observer with fast convergence.Secondly,a dual closed-loop control system is employed,with inner-loop differential flatness control and outer-loop improved super-twisting sliding mode control.This control strategy not only enhances the dynamic response of the system but also suppresses chattering using a higher-order sliding mode control algorithm,while addressing the non-minimum phase problem in the boost mode of the converter.Next,the stability of the control system is proven using Lyapunov theory.Finally,the control strategy is validated through simulations using MATLAB/Simulink software and an experimental platform.The results demonstrate that the proposed control approach effectively mitigates disturbances and improves the transient performance of the system.

关 键 词：双向DC-DC 三相交错 级联有限时间扩张状态观测器 微分平坦控制 改进型超螺旋滑模控制 

分 类 号：TM46[电气工程—电器]