Buck变换器的滑模控制研究（孙明志）.ppt

1、Thursday, August 13, 2020,The College of Information Science and Engineering,答辩人 ：孙明志,指导教师 ：郑艳 副教授,Buck变换器的滑模控制研究,Thursday, August 13, 2020,The College of Information Science and Engineering,绪论,Buck变换器的工作原理与数学模型,Buck变换器的自适应积分滑模控制,Buck变换器的自适应动态滑模控制,结论与展望,Thursday, August 13, 2020,The College of Infor

2、mation Science and Engineering,课题背景及研究意义,由于开关电源在重量、体积、 能耗等方面都比线性电 源有显著减少，因此开关电源的应用得到了迅速推广， 但 是常用的PID控制系统对系统参数的变化比较敏感，当负载 大范围变化时，开关变换器存在动态响应速度慢、 输出波 形有畸变等缺点。 而滑模控制的变换器具有稳定范围宽、动态响应快、 鲁棒性强等优点，成为研究的热点。,Thursday, August 13, 2020,The College of Information Science and Engineering,Buck变换器的工作原理与数学模型,Thursda

3、y, August 13, 2020,The College of Information Science and Engineering,Buck变换器的工作原理,图2.1Buck变换器电路,Thursday, August 13, 2020,The College of Information Science and Engineering,开关T导通时,图 2.2 开关T导通时的Buck电路图,Thursday, August 13, 2020,The College of Information Science and Engineering,开关T关断时,图2.3 开关T关断时的Bu

4、ck电路图,Thursday, August 13, 2020,The College of Information Science and Engineering,Buck变换的数学模型,为考虑了负载变化的不确定参数且假设,(2.1),取x1为误差电压，x2为电容电流,其中,(2.2),Thursday, August 13, 2020,The College of Information Science and Engineering,Buck变换器的自适应积分滑模控制,Thursday, August 13, 2020,The College of Information Science

5、 and Engineering,考虑如下不确定的二阶系统,(3.1),问题描述,积分型切换函数设计为,(3.2),(3.3),Thursday, August 13, 2020,The College of Information Science and Engineering,滑动模态方程为,(3.5),积分滑模控制器设计,(3.6),稳定性分析,(3.7),Thursday, August 13, 2020,The College of Information Science and Engineering,设计自适应律为,(3.9),(3.8),稳定性分析,(3.10),自适应积分滑模

6、控制,控制器设计,(3.11),Thursday, August 13, 2020,The College of Information Science and Engineering,的摄动，原系统变为,考虑系统参数,(3.12),其中,将式(3.8),(3.12)代入,可得,改进的自适应积分滑模控制器,(3.13),Thursday, August 13, 2020,The College of Information Science and Engineering,改进的控制器为,(3.14),设计自适应律为,(3.15),(3.16),Thursday, August 13, 2020

7、,The College of Information Science and Engineering,稳定性分析,(3.17),(3.18),Thursday, August 13, 2020,The College of Information Science and Engineering,Buck变换器的自适应积分滑模控制器,(3.21),仿真研究,(3.22),Buck变换器改进的自适应积分滑模控制器,系统参数,Thursday, August 13, 2020,The College of Information Science and Engineering,图3.1 输出电压x

8、1的变化曲线 图3.2 输出电压x1的局部放大图,结论：积分滑模控制的快速性明显好于常规滑模控制并且有 效地消除了静差,Thursday, August 13, 2020,The College of Information Science and Engineering,图3.3 输出电压x1的变化曲线 图3.4 输出电压x1的变化曲线,结论：当负载变化时，自适应积分滑模控制有效提高了系统 的快速性，增强对负载变化的鲁棒性。,负载R=100,负载R=1,Thursday, August 13, 2020,The College of Information Science and Engin

9、eering,图3.5 自适应积分滑模控制 图3.6 改进的自适应积分滑模控制 输出电压x1的变化曲线 输出电压x1的变化曲线,1V阶跃扰动时,Thursday, August 13, 2020,The College of Information Science and Engineering,图3.7 输出电压x1的变化曲线 图3.8 输出电压x1的放大图,1V正弦扰动时,结论：改进后的自适应积分滑模的稳态性能明显的提高,Thursday, August 13, 2020,The College of Information Science and Engineering,Buck变换器的

10、自适应动态滑模控制,Thursday, August 13, 2020,The College of Information Science and Engineering,考虑如下线性二阶系统,(4.1),定义切换函数为,(4.2),问题描述,由,求得等效控制为,(4.3),Thursday, August 13, 2020,The College of Information Science and Engineering,(4.4),滑动模态方程为,采用等速趋近律,则动态控制律为,(4.5),(4.6),Thursday, August 13, 2020,The College of I

11、nformation Science and Engineering,考虑不确定二阶系统,(4.8),滑动模态方程变为,(4.7),此时，不确定参数 被引入到滑动模态方程中，对系统 的性能产生影响。,Thursday, August 13, 2020,The College of Information Science and Engineering,定义切换函数,(4.9),其中,为对系统中未知参数,的估计,自适应动态滑模控制器的设计,滑动模态方程为,(4.10),Thursday, August 13, 2020,The College of Information Science and

12、 Engineering,改进的控制器的设计,定义含不确定参数的状态,的观测器为,其中,(4.11),(4.12),自适应律为,(4.13),动态滑模控制律,Thursday, August 13, 2020,The College of Information Science and Engineering,稳定性分析,(4.14),(4.15),Thursday, August 13, 2020,The College of Information Science and Engineering,Buck变换器的自适应动态滑模控制器,仿真研究,系统参数为,Thursday, August

13、13, 2020,The College of Information Science and Engineering,负载R=100,图4.1 动态滑模控制输出电压x1 图4.2 自适应动态滑模控制 的变化曲线 输出电压x1的变化曲线,Thursday, August 13, 2020,The College of Information Science and Engineering,图4.3 输出电压x1的变化曲线 图4.4 输出电压x1的变化曲线图,负载R=1,负载R=10K,结论：负载变化时，自适应动态滑模控制的动态性能明显优于 动态滑模控制，提高了系统对负载变动的鲁棒性,Thurs

14、day, August 13, 2020,The College of Information Science and Engineering,图4.5 控制量d(t)的变化曲线,负载R=100,Thursday, August 13, 2020,The College of Information Science and Engineering,图4.6 观测器跟踪误差变化曲线,负载R=1,Thursday, August 13, 2020,The College of Information Science and Engineering,结论与展望,Thursday, August 13, 2020,The College of Information Science and Engineering,结论 改进的自适应积分滑模控制器，消除了Buck变换器输出电压的静差，提高了输出电压的精度 。解决了设计中必须知道负载上界的约束，提高了负载变化时系统的性能。 动态滑模控制可以使Buck变换器中控制量的抖振大幅降低，但削弱抖振的同时也削弱了系统的鲁棒性。 Buck变换器的自适应动态滑模控制，在削弱系统抖振的同时，有效弥补了