锥形磁悬浮轴承的建模与解耦控制  

Modeling and Decoupling Control of Conical Magnetic Bearings

作　　者：高琳[1] 徐宗海[1] 朱凯[1] 李黎川[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049

出　　处：《中国电机工程学报》2013年第6期153-160,21,共8页Proceedings of the CSEE

摘　　要：磁悬浮轴承的标准结构包括两个径向轴承和一个轴向轴承,也可以将两个径向轴承做成锥形使其能够提供轴向悬浮力,从而省去轴向轴承,减小磁悬浮轴承的轴向尺寸,并使系统结构简化。但仅仅依靠两个锥形径向轴承使转子悬浮,在磁轴承的轴向和径向间会存在很强的耦合,使系统的建模和控制都变得更复杂。对一台自行设计的锥形磁悬浮轴承提出一种解耦控制。首先采用磁路法建模,得到原始的非线性模型。然后对非线性模型进行线性近似,并通过引入输入与输出的线性变换使系统解耦,推导出5个单输入单输出的解耦控制模型,分别对应于转子的5个运动自由度。最后,针对这5个被控对象分别设计控制器,并对解耦控制进行仿真分析和实验验证。结果表明,锥形磁悬浮轴承可以通过对其输入和输出进行简单的代数变换实现有效的解耦。Standard configuration of a magnetic bearing involves a pair of radial bearings and an axial one. It is also possible to let the two radial bearings have a conical shape, and provide axial suspending forces as well. Then the axial bearing can be omitted, and the magnetic bearing will have less axial size and simpler constructions than a standard magnetic bearing. Suspending a rotor by only a pair of conical-shaped radial magnetic bearings, however, introduces strong coupling between the axial and radial directions, which renders the modeling and control more complicated. This paper presents a decoupling control for a self-designed conical magnetic bearing. The magnetic bearing is first modeled by using a magnetic circuit method. Then the model, which is nonlinear in its original form, is approximated by a linear one, and decoupled by linear transformations on the inputs and outputs. This gives five single-input single-output plants, representing the five motion axes of the rotor. Finally, five controllers are designed, respectively, for the five plants. The decoupling control is tested by both simulations and experiments, showing that a conical magnetic bearing can be decoupled effectively through simple algebraic transformations on plant inputs and outputs.

关 键 词：锥形磁悬浮轴承 线性化 建模 解耦控制 

分 类 号：TM343[电气工程—电机]