大间隙磁力传动装置的控制系统研究

【作者】 刘云龙；

【导师】 谭建平；

【作者基本信息】 中南大学 ， 机械电子工程， 2009， 硕士

【摘要】 磁力传动是以永磁材料或电磁机构产生的磁力作用实现力或力矩非接触式传递的一种新技术,克服了机械传动中机件磨损的严重缺陷,具有机械式传动无可比拟的优势。目前,磁力传动的研究主要是基于主、从磁极间距为小间隙的磁力传动系统的磁场分布、传递电磁转矩等方面,在人工心脏的驱动研究过程中,外磁场驱动方式的提出有效地解决了以往血泵供能系统的不足,通过非接触式磁场驱动,解决了一系列传统血泵驱动方式难以克服的工程和医学上的困难。本文以当前国内外磁力传动技术研究成果为平台,大间隙磁场驱动轴流式血泵为研究对象,心室功作为血泵输出的控制目标,提出了一种基于行波磁场的主动磁极静止式大间隙磁力传动系统,用电磁体代替“电机-永磁转子”结构,避免了高频率、高转速下由于电机易损坏的缺陷,使得结构简单、可传动间隙大、可靠性和实用性好,具有重要的创新意义。通过对这种全新的驱动方式的探索研究,提出了用以实现交变磁场的静止式电磁体机械结构,并基于单片机设计了驱动控制电路,通过理论和实验相结合,计算能量传递效率。主要研究内容如下:1.基于主动磁极静止式的驱动思想,设计电磁体机械结构,根据电磁场相关理论,建立电磁体在空间某处产生的磁感应强度的数学模型,据此确定最佳的电磁体设计参数;2.分析电磁体同血泵永磁转子的空间磁场耦合过程,得出电磁体线圈的脉冲控制方式,基于单片机,设计驱动控制电路,编写控制程序,并通过仿真软件预先修正电路中各元件参数,指导电路板的制作;3.以计算电磁学、电磁场机电能量转换为基础,通过对大间隙磁力驱动系统能量传递过程的分析,得出能量传递各部分功率损耗,建立磁场能量传递效率的数学模型;4.搭建血泵综合实验台,进行血泵驱动实验,得到输出电流与血泵转速、泵水高度的对应关系曲线,根据实验结果以及建立的磁场能量传递效率模型,计算大间隙磁力传动系统的能量传递效率,为磁能量传递规律的进一步深入研究奠定了基础。更多还原

【Abstract】 Magnetic drive is a new technique which uses permanent magnetic material or electromagnetic mechanism produce magnetic force to realize the force or moment non-contact transfer. It has conquered the critical defect of work-pieces’ attrition in mechanical drive, and has the unexampled advantage of mechanical drive. At present, the research of magnetic drive, such as the magnetic field of magnetic drive system and transfer electromagnetism torque, is primarily based on small gap between the initiative magnetic pole and the passive magnetic pole. At the process of mechanical heart drive research, it is the very extracorporeal magnetic driving method that effectively resolves blood pump’s shortage for lacking of energy. Through the non-contact magnetic driving method, a series of difficulties on engineering and iatrology have been solved, which used to be an insurmountable drawback for tradition blood pump driving mode.In this paper, the research findings on magnetic drive technique of home and abroad is used as reaearch platform, and large gap magnetic drive axial flow blood pump as the research target and ventricular work as control objective of blood pump’s output, a large gap magnetic drive system, whose initiative magnetic pole keeps static, was presented based on traveling wave magnetic field. This structure uses electromagnet instead of motor and permanent magnet, avoiding the defect for easy damage of motor under the condition of large gap and high speed. Besides, its construture is simple, and it will have the larger drive gap, better reliability and practicability, and significant innovation.Through research on this bran-new driving means, a statically electromagnet mechanical structure is proposed to realize alternating magnetic field. Based on Single Chip Micyoco (SCM), the driving control circuit is designed. Combining theoretics and experimention, energy transfer efficiency of the system is calculated. The main research contents are introduced as following:1. Based on the driving thought, in which initiative magnetic pole keeps static, designing the electromagnet mechanical structure. According to the related theory on electromagnetic field, establishing the mathematical model of magnetic induction which is produced in space somewhere by the electromagnet, and confirming its first class design parameter.2. Through analysing coupling process of magnetic field in space between blood pump and permanent rotor, gainning the pulse control mode of electromagnet coil. Based on SCM, the driving control circuit is designed, and the control program is writed. Using simulation software to modify the elements parameter in circuit, by which guiding the manufacture of circuit board.3. On the basis of computational electromagnetics and electromechanical energy conversion of electromagnetic field, the power dissipation of each energy transfer portions are getted out, and the mathematical model of magnetic field energy transfer efficiency is established, according to the analysis of energy transfer process in large gap magnetic drive system.4. The comprehensive experimental bench of blood pump is built. According to the experiments of driving blood pump, acquiring the relation curves between rotating speed of blood pump and water column height, and the relation curves between deferent current and water column height. Based on the experimental results and the mathematical model of magnetic field energy transfer efficiency, the energy transfer efficiency of large gap magnetic drive system is calculated, so as to lay a foundation for the further research on the law of the magnetic field energy transfer.更多还原