【作者】 管晓文；

【导师】 黄守道；

【作者基本信息】 湖南大学 ， 电气工程， 2009， 硕士

【摘要】 永磁型无轴承电机是永磁交流电机与电磁轴承相结合的产物。它是根据交流电机定子与电磁轴承结构的相似性,把电磁轴承中产生悬浮力的绕组直接嵌入交流电机定子内部,利用悬浮绕组产生的气隙磁场来改变电机原有气隙磁场的分布,使其中一部分磁场增强,与其相对的部分磁场减弱,这样,不平衡的气隙磁场将在电机转子上产生一沿气隙磁场增强方向上的悬浮力,实现转子的悬浮。永磁型无轴承电机具有无摩擦、无磨损、无润滑、结构紧凑、尺寸小、功率密度大等一系列优点,在生命科学、航空航天领域具有潜在的应用前景,因而受到各国学者的高度重视。永磁型无轴承电机根据其转子结构形式的不同可以分为表贴式、插入式、内置式等种类,其中表贴式结构转子由于具有结构简单、永磁体易于优化设计、隐极电磁结构的优点已成为当今永磁型无轴承电机研究的热点。本文对表贴式转子结构的永磁型无轴承电机控制系统进行了较为深入的研究。文章针对传统的基于转矩绕组转子磁场定向解耦控制策略悬浮力算法复杂、悬浮力与控制电流不具有线性关系的缺陷,基于悬浮力产生机理,提出了一种基于转矩绕组气隙磁场定向的解耦控制策略,有效解决了转子磁场定向控制所存在的缺陷。针对传统悬浮控制子系统存在悬浮力延时的缺陷,基于经典控制理论中的前馈控制思想,在悬浮控制子系统中引入悬浮力前馈补偿控制环节,有效地消除了悬浮力延时。最后针对机械式位移传感器固有缺陷影响电机转子悬浮性能的问题,根据悬浮绕组气隙磁链互感分量中含有转子径向位移信息的特点,提出了一种旋转坐标系中利用悬浮绕组气隙磁链互感分量计算转子径向位移的转子位移自检测方法,实现了永磁型无轴承电机无位移传感器稳定运行。更多还原

【Abstract】 The permanent magnet type bearingless motor(PMBLM) is the combination of the permanent magnet type AC motor with the electromagnetic bearing. According to the similar structure of the AC motor’s stator with the electromagnetic bearing, it embedded the windings which are used to produce suspension force in the electromagnetic bearing into the stator of AC motor, using the flux produced by the suspension windings to change the original flux distribution of the AC motor, making the flux density increase in some part of the air-gap, but decrease in the counter part, then the unbalanced distribution of the flux density will generate suspension force on the rotor towards the direction where the flux density increased, the force realized the suspension of the rotor. The permanent magnet type bearingless motor has been paid close attention due to its potential application prospect in the filed of life sciences, aviation, et al, because of its advantages of frictionless, abvasionless, lubricationless,compact structure and high power capability.The permanent magnet type bearingless motor can be classified in to three types based on the different structure of rotor. These are surface mounted magnet type, inset magnet type and interior magnet type. Compared with the other two types, the surface mounted magnet type has advantages of simple structure, magnet being prone to optimized non-salient electromagnetic characteristics. This paper has made in-depth study on the control strategy of the surface mounted magnet type PMBLM.IN view of the complexity of suspension force model and the nonlinear relationship between suspension force with its control current of the traditional control algorithm based on the motor rotor flux orientation, a decoupling control strategy based on motor air-gap flux orientation was proposed in this paper based on the principle of suspension force production, it found that it can successfully untie the limitation of the rotor flux orientation control strategy.There exists time delay in suspension force of the conventional suspension control system. Based on the feedforward control theory, a feedforward compensation tache of suspension force was introduced in the suspension control system, the time delay in suspension force was successfully eliminated.At last, in view of the problem that the inherent limitation of mechanical displacement sensor influences the motor’s suspension characteristics, according to the characteristics that the mutual flux component of suspension windings contains rotor radial displacement information, a rotor radial displacement estimation scheme using the mutual flux component of suspension windings in rotary coordinates was proposed in this paper, it fond that it is able to achieve stable sensorless suspension operation.更多还原