【作者】 高哲；

【导师】 郑艳；

【作者基本信息】 东北大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 DC-DC变换器是一种直流电变换装置,能够快速有效地将输入直流电压变换到理想的输出直流电压,实现输出电压的可控调节。由于DC-DC变换器具有能量利用率高、电子元件少等优点,在很多行业中得到广泛应用。DC-DC变换器是一个非线性时变系统,建模、稳定性分析和输出动态品质的分析一直是一个研究热点。在各种动态品质中,系统输出的快速性和鲁棒性尤为重要。滑模控制对于系统参数摄动和外干扰具有很强的鲁棒性,得到广泛的应用。为了提高系统输出响应的快速性和鲁棒性,本文针对最DC-DC变换器设计了快速滑模控制器全程鲁棒滑模控制器。本文的主要内容如下:针对最基本的DC-DC变换器—Buck变换和Boost变换器,分别分析了变换器电路的工作原理,并建立了状态空间数学模型。为了提高系统相应的快速性,针对电源端含有纹波干扰的Buck变换器给出了一种非奇异终端滑模控制器,以加快系统的响应速度和消除系统的奇异现象。此外给出了自适应非奇异终端滑模控制器和自适应律,通过在线对干扰上界进行估计解决了干扰上界未知的问题。为了减小系统的抖振现象,提出了一种改进的终端滑模控制器,不但减弱了系统抖振强度而且保留了终端滑模快速性的优点,同时给出了减小稳态误差的方法。实际的控制系统大多采用计算机控制。为了实现计算机控制,针对电源端含有纹波干扰的Buck变换器提出了离散时间全程滑模控制器,实现了全程鲁棒控制,提高了系统输出电压的鲁棒性。为了减弱系统的抖振现象,给出了一种改进的离散趋近律,通过改进的趋近律设计的控制器不但减弱了系统的抖振现象而且减小了系统稳态误差。Boost变换器的状态空间平均模型是一个仿射非线性模型。针对这类非线性系统,提出了一种精确化建立T-S模糊模型的方法,给出了一种基于T-S模糊模型的积分滑模控制器,并将滑模控制方法推广于控制矩阵不相等的T-S模糊系统中,使系统状态在初始时刻就落在滑模面上,实现了全程滑模控制,提高Boost变换器电压输出的鲁棒性。最后对本文的研究内容进行了总结,并对未来的研究方向进行了展望。更多还原

【Abstract】 DC-DC converter is an electric device which can convert direct voltage of the system input to any reference value fast and effectively, and it has been applied to many areas. DC-DC conventer is a nonlinear and time-variable system, so how to build the system model, the analysis of stability and output dyanamic behavior are important research aspects. In all of the dyanamic behaviors, the fastness and robustness are more impotant than others. Sliding mode control has gradually been applied to many areas extensively for its strong robustness to system perturbations and external disturbances. The fast and robust sliding mode controllers are designed respectively to enhance the fastness and robustness of the output value for the DC-DC conventer. The main contributions are as follows.The basic theory of two typical DC-DC converters-Buck converter and Boost converter are analysed and mathematical models are given.The nonsingular terminal sliding mode controller is desigened for the Buck converter with input disturbance to enhance the output response without the singularity. When the upper bound of the input disturbance is unkowned, the above controller is invalid. Then, adaptive nonsingular teminal sliding mode controller is desigened to solve the problem. An improved terminal sliding mode controller is desigened to lower the chattering phenomenon and it can also lower the system steady state error by adjusting controller parameters.In many practical control systems, the plant is controlled by the computer. The discrete-time global sliding mode controller of the Buck converter with input disturbance realizes computer control and global robust control. A discrete-time global sliding mode controller based on improved reaching law is designed to lower the chattering phenomenon and it also can lower the system steady state error.The state space average model of the Boost converter is an affine nonlinear system. An accurate modeling method of the T-S fuzzy model is presented for this nonlinear system. An integral sliding mode controller is designed based on the T-S fuzzy model to enhance system robustness and this approach can be applied to the T-S fuzzy model whose contol matrice are inequal. At last, the conclusions are drawn, and the further research directions are presented.更多还原