受扰直流降压变换器自适应离散滑模控制设计与实现

Adaptive discrete-time sliding mode control design and implementation for DC-DC buck converters with disturbances

直流变换器在能量转换系统中起到至关重要的作用.针对直流降压变换器系统中存在的多源干扰问题,本文提出了一种基于观测器的复合离散滑模控制方案.为获得高电压跟踪精度和强抗干扰能力,在控制器中引入了干扰估计信息的二阶差分.通过干扰估计和前馈补偿,有效地消除了干扰对变换器电压跟踪精度的影响.同时,为削弱抖振影响,文中设计了一种新型的自适应滑模趋近律,并针对闭环系统给出了严格的稳定性与收敛性能分析.此外,本文基于快速原型控制器进行不同工况下变换器系统实验测试.结果表明,相比于传统离散滑模控制,文中所研究的复合控制器具备较强的抗干扰能力和较高电压跟踪精度.

DC-DC converters have been serving as indispensable components in energy conversion process,which play important roles in energy saving and efficiency promotion.In this paper,the output voltage regulation problem is addressed by applying disturbance observer based the adaptive discrete-time sliding mode control(ADSMC)algorithm.The tracking accuracy and disturbance rejection ability are significantly improved by introducing the second-order difference of disturbance estimations into the controller,which is provided by a novel discrete-time disturbance observer.The effects of disturbances are removed from the output voltage channel.Furthermore,an adaptive reaching law is implemented instead of constant gain to alleviate the control input chattering.Both dynamic and steady-state performance analysis are presented.Finally,experimental results are illustrated to demonstrate the elegant control performances.The comparative results show that stronger disturbance rejection ability and higher voltage tracking performances can be achieved even in the presence of multiple disturbances.