高温超导磁悬浮轴承中英文对照外文翻译文献
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中英文资料翻译
REVIEW ON INTERNATIONAL RESEARCH STATE ON HIGH TEMPERATURE ACTIVE MAGNETIC BEARING Radial active magnetic bearing (AMB) is a typical system in magnetic suspension field. The active magnetic bearing can support a rotor without contact by using electromagnetic force. With the advantage of unlubricated, little oil contaminated, long life-span and the adaptability of various environment, AMB is widely used. So the research on AMB is more and more further. It is reasonable to design the structure of active magnetic bearing properly for the improvement of its performance. Based on finite element analysis software COMSOL Multiphysics, the simulation of AMB is studied while the suspending force of AMB is calculated. First, we built up a dynamic parameter model, so we can analyze the magnetic field distribution and magnetic force at an arbitrary size. Then we discussed some element which affect magnetic field such as coil current, air gap, pole width and rotor bias under two working mode. Then the optimization process of AMB model is presented on the basis of optimization software iSIGHT together with COMSOL, during which the AMB model is called automatically by iSIGHT. We used sequential quadratic programming method and the result shows that the combination of COMSOL Multiphysics and iSIGHT software is a convenient and effective method for the simulation and optimization of AMB system. At last, we used PID controller to realize the close-loop control on single degree of freedom AMB system, and analyze the performance of PID controller with the simulation result on Simulink. Through the research above, we finish the design of the whole active magnetic bearing system.
The research result provides a feasible method for the analysis and optimization of AMB system, which will be useful for the engineering application.
In the past few years, the aviation industry has been growing continuously, but the market is very competitive is always necessary. High temperature active magnetic bearing hold great promise for improving jet turbine engine, and thus reducing maintenance cost and kerosene consumption. In that goal, lots of research has been performed about high temperature active magnetic bearing and its components(like soft magnetic material, insulation coils···).This article presents the development of research in this field, its history, its state and its outlook.
The aviation market is nowadays growing continuously. In order to sustain its development, this market has a constant need of technical improvements to improve competitiveness.
Today, virtually all aircraft’s jet engines use lubricated ball bearings. This system suffers from diverse drawback like the necessity of a complex cooling system that weighs down the jet engine and limits its working temperature.
Active magnetic bearings have been successfully used for decades in numerous applications. They have shown great capacities to work in extreme conditions, such as vacuum or at high rotation speed. The idea is to replace the conventional bearings in jet engines by magnetic bearings.
In the 90 s, the majority of magnetic bearings were working under common temperature(less than 100℃).In jet engines, the current working temperature is about 260℃, thus proving feasibility of magnetic bearings for jet engines application was required. In the same time research were performed on soft magnetic material for high temperature applications, the proof of feasibility of magnetic bearing working at 550℃was done by Xu Longxiang.
Using high temperature active magnetic bearing may significantly improve the jet engines.
First this technology will allow operating at much higher speeds and temperatures(up to 550℃), opening space for design of more powerful jet engines. Since AMB are non-con-tact bearings, there is no more need for lubricant. Removing
the lubricant system will make the system more fire-safe (no possible oil emissions) and also improve the weight of the engine (up to 5% less). This, added to the elimination of friction losses, will have direct influence on the kerosene consumption.
The objective of this article is to present the recent development on high temperature magnetic bearing.
The development of high temperature magnetic for jet engine application includes diverse research project, with three main projects.
In 1997, Kondoleon has been studying soft magnetic alloys for high temperature radial magnetic bearings. Xu Longxiang has then demonstrated the feasibility of an active magnetic bearing working at 540℃and investigate high temperature displacement sensor. In 2000, Mekhiche briefly described the design, fabrication, and testing of a high-temperature magnetic bearing operating at 50 000 rpm. In 2003, Montague has worked on a prototype of high temperature active magnetic bearing and develop a coil fabrication process. In 2006, Burdet has developed a first 5 degree of freedom high temperature active magnetic bearing and investigate an eddy current position sensor using thick-film technology.
The three main projects that have been investigating high temperature active magnetic bearing are:
-The European project for Active Magnetic Bearings in Aircraft Turbo-machinery (AMBIT) from 1995 to 2000,
-A project of Design and Fabrication of High-Temperature Radial Magnetic Bearing for Turbo Machinery by the NASA from 2000,
-The European research project MagFly-Active Magnetic Bearing for Turbo Machinery from 2002 to 2006.
The objectives of AMBIT were to investigate and to demonstrate the feasibility of an active magnetic bearing that works at temperatures up to 540℃. A one-degree-of-freedom high temperature AMB rig was built as well as a five-degree-of-freedom prototype with a high temperature radial bearing.
Here is the test rig for a high temperature active magnetic bearing, operating in
a containment heated up to 550℃and running at 30 000 rpm.
Glenn H. Research center works presently on a high temperature AMB. It is a high temperature, heteropolar, radial magnetic bearing composed of a single radial bearing located at the center of a shaft mounted on ball bearings. It has been operated for 29 hours at 540℃during 18 thermal cycles on May 2003.
This project has been created with the goal of developing a smart jet engine using magnetic bearings. Part of it was to develop an AMB prototype working at high temperature.
For this project, Luc Burdet has developed the first 5 degree of freedom high temperature active magnetic bearing. It has been running at environment temperatures up to 550℃.
During his thesis, he has implemented and validated a modular finite elements thermal model with low computation time for high temperature AMBs. He has also developed a thick-film low cost eddy current position sensor for 550℃applications and tested materials for the design of high temperature electromechanical system have been tested. In addition, an analysis of failures related to high temperature has been done and illustrated.
While the AMBs developed in AMBIT satisfied the requirements, problems were encountered with overheating and coil short circuits. Those problems have been partially resolved by Montague, which has developed a coil manufacturing process. In this process, in order to reduce the difficulty of wounding the coils on the back-iron core, choice has been made not to use stator lamination leg designed as one continuous ring. Instead, a modular design where each module contains two poles in “C” shape has been chosen. The wire is wound on both poles continuously, eliminating many connections. The material used for the stator laminations is Hiperco 50 (the commonly used silicon steel cannot be chosen here because its Curie temperature is too low), while 99.9-percent-pure annealed silver wire was chosen. Wire insulation is critical point for high temperature actuators. It requirements are the following: a good thermal conductor, flexible, compact and supporting
temperatures up to 800℃. It must protect the conduct integrity and keep from cracking or flake off. It must also have good toughness and scratch resistance to avoid turn-to-turn short-circuit. Finally, the authors used a commercially available, two –compound, clear ceramic coating. At the end, the coil windings are encapsulated and bonded with an alumina based ceramic potting compound.
Another critical point of the high temperature magnetic bearing is the development of a reliable position sensor. Common sensors cannot be used because of the influence of temperature on material properties. This problem has been studied by Burdet which has developed an eddy current position sensor using thick-film technology. The objective was to find a working solution for 550℃. Small inductors have been printed on Al2O3substrates. A conducting layer is printed as insulation. A second conducting layer is then printed. Both conducting layers are connected together in the centre of the coil. In the case radial sensor, the sensitivity is directly related to the inductor.
A prototype sensor of silver with 200μm track width, with silver wires and silver paste wire connections has been tested. Tests have shown that after 600 hours in a furnace at 550℃the sensor inductance and resistance suffer very little changes. However, problem has arisen due to silver migration. Sensors have to be connected to leading wires, and that point is much more critical, with dendrites are growing quite fast between the two connector pads at high temperature, and thus creating short circuit. Solutions to slow down this effect have been tested. While covering the conductor layer and the soldering with a dielectric, sensors are still working after 700 hours at 600℃.
The sensing principle of the radial sensor is based on two planar coils pasted on a substrate. The excitation coil embraces the rotor. It is supplied with an AC current source in order to create a high frequency magnetic field. Eddy currents are created on the rotor surface.
The position measurement is done differentially. Two coils facing one to the other are connected together in series, so that when the rotor is centered, the output signal is zero. When the rotor is moving from the middle position, a voltage is
measurable. The signal amplitude is proportional to the position and the measured signal sign is related to the displacement direction. The radial position sensor is thus able to measure along two orthogonal axes. Unfortunately, sensor noise appears after a short time due to silver migration.
Magnetic fluid is a new type function material which is both magnetic and liquid, and it’s the only super-paramagnetic material at room temperature. Magnetic fluid accelerometer is an application of magnetic fluid’s self-levitation theory, and its structure is simple and reliable. With the advantage of detecting low frequency acceleration, magnetic fluid accelerometer could be widely used in military and aerospace. The main work of this thesis is as follow:
——Magnetic fluid’s self-levitation is analyzed; Dependence of levitation on dimension of magnets and accelerometer’s shell, volume and saturation magnetization of magnetic fluid are give out by experiments which show the main factors that influence levitation force are the dimension of magnets and the volume of magnetic fluid.
——The influence of the two factors on the sensor is given out.
——The structure of accelerometer is designed by conclusion of experiments.
——The frequency of exciting signal is given out by experiment. Finally, the circuit of sensor is designed.
——The sensor is tested which show the sensor’s sensitivity is 15.3V/g.
Dependence of the self-levitation force on several factors are given out, the structure and circuit of accelerometer are designed and the accelerometer is tested. It’s a good foundation for next work.
In order to investigate the dynamic characters influenced by the base vibration, the stiff base-active magnetic bearing (AMB)-rotor system model is set up. The stability of the rotor is analyzed in the conditions of different exciting amplitudes and frequencies of the base vibration. It is clear that the rotor become unstable when the vibration is becoming smart. Compared with the dynamic character of the rotor without base vibration, the results show that the base vibration influence on the dynamic character cannot be ignored. The base vibration not only causes the
rotor axis deviate from the absolute position, but also causes the stiffness and the precision of the rotor fall. Moreover, if the base vibration is drastic, the AMB will lose the supporting ability. So the base vibration must be considered in model building and controller designing process.
In the future, the main research field will have to be explored for the development of high temperature active magnetic bearings.
First of all, it now exist very few data about materials for high temperature applications. Before the component can be put into a system, its behavior under working condition has to be checked. It is really time consuming, as time and thermal cycle are important parameters for material life span. Iterative development in order to acquire data about high performance and high life span material for high temperature applications is a primordial need for further AMB research.
Another very important point is the development of reliable position sensors. The one developed by Burdet met the requirements, but as problem arise due to silver migration, levitation was not possible for more than a short time.
Another field to investigate is the long term influence of temperature on the system behavior. Until now, only short term tests have been performed, and most of them were without rotation. Studying the system comportment under real working condition will be the next step of high temperature active magnetic research.
This article has presented the current state of research in the field of high temperature active magnetic bearing.
Future works in this domain will need to continue studying material fabrication process and their properties at high temperature with more realistic working conditions and to develop a more robust new sensor for high temperature application. Also, study must be done on the long-term effect of high temperature and stress on the system behavior.
回顾国际高温超导磁悬浮轴承的研究状况在磁悬浮领域中,应用最广泛的就是磁悬浮轴承。
它是利用电磁力将转轴悬浮在磁场中,使转子在空间无机械接触、无磨损地旋转的一种新型高性能轴承。
由于具有无需润滑、无油污染、寿命长以及适用于许多应用环境等优点,因而具有一般传统轴承所无法比拟的优越性,因此近年来国内外对其研究都颇为重视。
为了提高磁悬浮轴承的性能,需要合理设计磁轴承的结构,这就要求对磁轴承的电磁场以及磁悬浮力有深入的了解,为此本文基于有限元分析软件COMSOL Multiphysics建立了主动磁悬浮轴承系统的有限元分析模型,通过仿真对磁悬浮轴承在单侧磁极作用和差动磁极作用两种工作方式下,激励电流、气隙宽度、磁极宽度、偏心等因素对其电磁力的影响进行了深入细致的探讨。
然后,本文探讨了一种将优化软件iSIGHT与COMSOL Multiphysics相结合来对磁悬浮轴承进行优化设计的方法,并采取序列二次规划算法对磁悬浮轴承进行了结构优化设计,得出了相应条件下磁轴承的最优参数,取得了满意的结果,从优化结果来看:COMSOL与iSIGHT软件相结合来对磁悬浮轴承进行分析设计是一个快捷、有效的方法.最后,为磁悬浮轴承系统建立单自由度的控制模型,本文采用经典的PID 控制策略来实现对单自由度磁悬浮轴承系统的闭环控制,并给出了闭环控制系统的仿真和分析结果,完成了整个磁悬浮轴承系统的设计。
本文的研究结果可以为磁悬浮轴承的电磁场分析和结构设计提供参考和依据,也为进一步的磁轴承的多物理建模和仿真分析以及多学科设计优化等提供了一个可行的途径,具有一定的现实意义。
近年来,虽然航空制造业经历了持续不断地发展,但是市场是充满各种竞争的,通常要对成本进行合理的优化配置。
高温超导磁力轴承在喷气涡轮发动机的改善中具有极好的前景,并且能减少设备的维护费用以及燃料损耗。
为了实现这
一目标,越来越多的关于高温超导磁力轴承及其相关组件的研究项目正在不断地开展(例如常温超导材料,绝缘线圈···)。
这篇论文将介绍了这一研究领域的发展状况,它的发展历史,以及它现在的发展情况和未来的市场前景。
今天,航空制造业正在持续不断地发展。
为了维持并推动它的发展,市场迫切地需要通过技术进步来提高市场竞争力。
现今,几乎所有的航空喷气发动机都是采用润滑球轴承这种方式。
然而这一系统如今正遭受着各种各样的缺陷的困扰,例如综合冷却系统的使用会增加喷气发动机的总重量并限制了他的工作温度范围。
近十年来,超导磁力轴承在众多的领域里得到了更为广泛的应用。
它们在极端的工作环境下仍然能展现出强大的工作能力,例如在真空环境和高速旋转等条件下。
这种用磁力轴承替代常规轴承的想法逐渐被提了出来。
在本世纪九十年代,有大量的磁力轴承适合在常温环境下工作(低于一百摄氏度)。
然而,在喷气发动机中,其当前的工作温度大约是二百六十摄氏度左右,因此提高磁力轴承在喷气发动机中应用的可行性是十分必要的。
在同一时期的其他研究中,对适合在高温条件下应用的常规磁性材料的研究正在被不断开展,其中,徐龙祥教授检验并论证了磁力轴承在五百五十摄氏度的环境下开展工作的可行性。
使用高温超导磁力轴承能在很大程度上提升喷气发动机的性能。
首先这一技术将允许在高温高速环境下的操作(超过五百五十摄氏度),因此它适合用来制造设计推力更加强劲、性能更加优越的喷气发动机以开展对外太空的探索。
由于超导磁力轴承是一种无接触的轴承,对于润滑剂的使用需求会越来越少。
由于无需润滑系统,这将使整个系统在高温下的运转更加的安全(不需要排放废气)并且降低了整个发动机的总重量(至少降低百分之五以上)。
这样,更多地消除了摩擦损耗,同时对燃油的损耗将会产生更加直接的影响。
这篇论文的目的是为了说明高温磁力轴承在当前市场上的发展状况。
高温磁力轴承在喷气发动机中的应用发展包含了多种多样的研究计划,其中包括三个主要的项目部分。
在一九九七年,康德莱恩已经发现了适合用于制造高温放射状磁力轴承的常温磁性合金。
徐龙祥随后又验证了高温超导磁力轴承在五百四十摄氏度条件下工
作的可行性并研究设计出相应的高温位置传感器。
在二零零零年,迈克赫克简略地描述了高温磁力轴承在每分钟五万转的条件下工作时的设计制造,装配及检测过程。
在二零零三年,蒙泰格制定了一个高温超导磁力轴承的标准并且研发了一种特殊的线圈制造处理工序。
在二零零六年,博得特研发了第一个具有五个自由度的高温超导磁力轴承和一种使用了薄膜技术的通用涡流位置传感器这三个研究高温超导磁力轴承的工程项目分别是:
——一九九五年到二零零零年,由欧洲开展的高温超导磁力轴承涡轮增压系统的航空器项目,
——二零零零年,由美国国家航空和宇宙航行局展开的高温放射状磁力轴承的设计与制造项目,
——二零零二年到二零零六年,由欧洲研究设计的高温超导磁力轴承涡轮增压系统项目。
设计高温超导磁力轴承涡轮增压系统的目的是为了研究和论证超导磁力轴承在五百四十摄氏度以上环境下工作的可行性。
一种单自由度高温超导磁力轴承设备已经像上述具有五个自由度的高温放射状轴承的标准一样被建立起来。
这是一种高温超导磁力轴承的检测设备,它是在一个密闭的,温度在五百五十摄氏度以上,转速在三万转每分钟的环境下工作的。
格伦研究中心目前正在设计一种高温超导磁力轴承。
它是一种高温,多磁极,放射状磁力轴承组成的位于球轴承杆件中心的一种单一放射状轴承。
在二零零三年五月份,直到第十八个热量循环周期完成为止,它已经在五百四十摄氏度的环境下连续工作了二十九个小时。
这个项目已经建立了一个用磁力轴承开发高灵敏度喷气发动机的目标。
其中的一部分是制定一个在高温下工作的高温超导磁力轴承的标准。
对于这个工程项目,拉克博得特研发了第一个五自由度高温超导磁力轴承。
它已经能够在超过五百五十摄氏度的环境温度下开展工作。
基于他的论文论点,他已经执行并且验证一种具有有限原理的热量模型标准化组件,并且对高温超导磁力轴承的运行进行了粗略的时间估算。
同时,他还开发设计了一种低成本的薄膜通用涡流位置传感器以适应在五百五十摄氏度环境下的工作,并且一种高温机电系统的设计检测材料已经处于测试中。
另外,一种
与高温有关联的对失败的测试结果进行分析的报告已经完成,其原因也在报告中被阐明。
然而,在高温超导磁力轴承涡轮增压系统的航空器项目中开发研制的高温超导磁力轴承对于调整的需要及要求还比较令人满意的时候,然而却突然遭遇到过热问题以及线圈电流回路短路问题的困扰。
开发出一种特殊的线圈制造加工工序的蒙泰格已经解决了这类问题其中一部分。
在这个工序中,为了解决减小对铁质衬里磁芯的损害这一难题,将不再采用先前的金属固定片层压薄膜材料支柱计划而是采用一种连续的环状设计。
取而代之的是,一种其中每个模块都包含两个C 型极性的组件设计已经被采用。
金属导线将连续不断地是所有的磁极受到损伤。
用来制造金属固定片层压薄膜的材料是Hiperco 50(通常使用的硅钢在这里不能选择使用是因为它的居里温度值太低的缘故),然而纯度达到百分之九十九点九的镀银金属导线却被选择使用。
金属丝绝缘层是实现高温驱动的关键因素。
他的要求如下所述:一个性能优良的热导体,是灵活柔韧的,紧凑密实的并且能够支持在超过八百摄氏度的高温环境下使用。
它必定要保持良好的导电性能并且能够杜绝破裂和剥落的现象的发生。
它同时还必须拥有十分出色的韧性和接触电阻以避免轮流反复的短路现象。
因此作者使最终决定采用一种在商业上可利用的,以两种复合的陶瓷材料制成的覆盖层作为金属导线的绝缘层材料。
最后,这些弯曲的金属线圈需要与一种基于陶瓷复合物而制成的氧化铝材料结合,并用胶囊将线圈包裹住。
使高温磁力轴承能够广泛使用的另外一个关键点是可靠性强的位置传感器的开发使用。
普通的传感器不能使用是因为温度会对材料的性能产生很大的影响。
已经制造出通用的薄膜涡流位置传感器的博得特已经对这个问题展开了研究。
他的目的是发现一种对于五百五十摄氏度环境下可行的解决方案。
一种小型的感应器已经被印刷在三氧化二铝的基底薄片上。
第一个传导层是在绝缘的状态下被印制上去的。
第二个传导层是在同样的状态下被接着印制上去的。
所有的传导层都与线圈的中心连接在一起。
装在箱子中的星形传感器,它的灵敏度与感应器是直接向关联的。
一个拥有两百微米轨迹宽度的银制传感器原型,使用银制导线和镀银导线之间的关联性正在被检测。
检测结果表明在五百五十摄氏度的熔炉中连续存放六百
个小时,传感器的感应系数以及阻抗值都只发生了极小的改变而已。
然而,问题已经出现在预期中的线性移动。
传感器不得不与线圈相联接,并且这一点是非常危险的,伴随着树枝状结晶在高温下两个接头装置衬垫之间的快速发展,从而造成线圈的短路。
减小这一影响的解决方案已经被相关人员检测。
然而通过对导体层的覆盖和对绝缘体的焊接,传感器仍然可以在六百摄氏度的环境下工作至少七百个小时以上。
这种星形传感器的传感原理是基于两个平面的线圈粘贴在同一个基底片层上。
励磁线圈缠绕在转子上。
它备有一个交流的通用电源以获得一个高频的交变磁场。
这种通用的涡流传感器被建立在转子的表面。
这种位置的检测在操作时是存在着差异的。
这两个线圈是通过串联的方式相互联接在一起的,以至于当转子处于居中位置的时候,其输出的电信号值为零。
当转子从中心位置偏离的时候,就会产生一个可以被检测的电压信号。
信号振幅与位置是成一定的比例的,并且测量信号的迹象与位移的趋势是直接相关的。
星形位置传感器从而可以在正交坐标轴中进行相关信号的检测。
遗憾的是,传感器噪声会在线性移动之后的一个很短的时间内出现。
磁性液体是一种新型的功能材料,它具有流动性与磁性材料的磁性,是唯一可以在常温下存在的液态超顺磁性物质。
磁性液体加速度传感器是利用磁性液体永磁悬浮理论设计的新型传感器,结构简单可靠且低频性能良好,被广泛应用于军事及航空领域。
本文主要研究工作包括:
——本文在详细分析磁性液体的永磁悬浮理论的基础上,实验研究了传感器外壳尺寸、永磁体尺寸、磁性液体的饱和磁化强度及其注入量对永磁悬浮力的影响,得出了磁铁尺寸及磁性液体注入量为永磁悬浮力的主要影响因素。
——根据实验结果,分析了以上因素对传感器性能的影响规律。
基于理论分析和实验结论,设计出了传感器的本体。
——实验研究了传感器励磁频率对传感器性能的影响,根据该实验研究结果设计出传感器的电路。
——最后,对传感器的性能进行了测试,得出其灵敏度大约为15.3V/g。
本文对磁性液体永磁悬浮原理的实验研究不仅为磁性液体加速度传感器设计进行了前期准备,而且为磁性液体二阶浮力原理的其它应用奠定了基础。
设计出的传感器
电路和传感器本体为本项目的后续研究提供了铺垫。
为了研究基础运动对磁悬浮轴承动态特性的影响,建立了刚性基础-磁悬浮轴承-转子的数学模型。
在不同的激励频率和振幅条件下对转自进行了稳定性分析。
结果表明,在激励频率和振幅超过一定的范围时,转自会失去平稳。
将计入基础运动与不考虑基础运动时的转子的运动特性进行对比,结果表明在磁悬浮系统设计过程中绝不能忽略基础运动对系统的影响。
基础运动不但会引起主轴轴心的绝对位置发生改变,而且基础的振动将导致主轴的刚度和精度下降,造成机床加工精度的降低。
另外基础振动可能造成转子失稳或者强烈振动,将导致磁悬浮轴承失去支承转子的能力。
因此在建模和控制系统的设计过程中必须充分考虑基础振动的影响。
在未来,主要的研究领域将是探索高温超导磁力轴承的发展道路。
首先,存在极少有关适合高温应用材料的资料。
在元件放入系统之前,它在现实工作条件下的状况将会被检验。
它的实时安排速度是强烈的,这是由于使用次数和热量循环是材料寿命的重要参数。
获得适合高温应用的高性能高寿命材料的数据是未来高温超导磁力轴承研究的需要。
另一个非常重要的一点是可靠的位置传感器的发展。
由开发的传感器成为了必需品,但是当问题上升到预期中的线性移动时,悬浮系统在短时间的稳定显得不太可能。
另外一个是为了验证温度对于系统反应的长期影响的领域。
到目前为止,只有短期的测试得以执行,它们大多数都在未检测的情况下运转。
研究现实工作条件下的系统状态将成为下一步高温超导磁力轴承的研究方向。
这篇论文说明了当前在高温超导磁力轴承领域的发展状况。
未来,在这一领域的工作将需要继续研究对制造加工材料的处理以及它们在更多现实的高温工作条件下的性能以开发出更完善。
的新式高温传感元件而且,必须研究高温高压对系统反应的长期影响。