【作者】 张建生；

【导师】 汪希平；

【作者基本信息】 上海大学 ， 机械设计及理论， 2006， 博士

【摘要】 本文主要研究磁悬浮支承系统功率放大器，包括其原理、特点、设计方法及应用技术，特别是专门应用于高档数控机床的运动机构，如高速高精度机床电主轴(旋转支承)及高速高精度平台(机床导轨)(平动支承)中的功率放大器。对于一个主动磁悬浮支承(轴承)系统而言，其中的核心理论和技术是主动磁悬浮理论及其支承技术，就其硬件部分来讲，主要由四大方面组成：位置传感与检测、信号控制与调节、电源与功率放大以及轴承与转子。本文在对当前磁悬浮支承(轴承)系统中的控制器技术及理论进行讨论的前提下，重点针对功率放大部分存在的问题和不足进行分析研究，并在此基础上提出相应的解决思路，同时，完成了切实可行的设计方案，包括采用线性器件构建的磁悬浮支承平台系统用的模拟功率放大器、采用开关器件构建的磁悬浮支承电主轴系统用的开关功率放大器；并对可能由于磁悬浮支承部件材料的B—H磁化曲线引起的电磁力非线性影响进行了分析讨论，提出了一种以克服这种非线性影响为目的的智能化功率放大器的构想，并讨论了其实现的可行性。论文主要以国家863计划项目“高档数控机床中的磁悬浮支承技术”(课题编号：2001AA423310)为依托，以其研究内容为本文的主要工作背景，以相关的理论分析及其实验数据为依据进行撰写，其中部分问题的提出则与国家自然科学基金项目“磁轴承智能化的机理及关键技术研究”(项目资助号：50475181)有一定的相关性。在磁悬浮支承系统中，稳定的悬浮(支承)力是依靠调整支承体(通常为电磁铁，在旋转机械中则称为轴承)激磁线圈中的电流来达到的，其中功率放大器的性能与支承系统的控制精度和技术指标密切相关。被支承体(在旋转机械中通常称为转子)与支承体之间的间隙是随着被支承体的高速运动而时刻发生着变化，需要实时地根据被支承体的位置情况对激磁线圈中的电流进行调整，达到稳定悬浮及可靠工作的目的。因此，主动磁悬浮支承系统中的控制器研究一度成为研究者关注的焦点之一。随着研究工作向实际应用方面的转变，功率放大器及其性能的优劣正在逐步成为应用者不得不关注的核心技术之一，也是决定磁悬浮支承系统性能的一个关键部件。目前在磁悬浮支承系统中流行的功率放大器主要有两大类：线性功放和开关功放。但由于两者的各自特点，在应用中应当说是各有利弊。另外，功率放大器输出通常采用差动式结构，以克服电磁力与线圈中电流之间的非线性影响。但磁性材料B—H曲线的非线性因素，在功率放大器做差动式输出时，也有可能会引起电磁铁吸力的不对称现象，给实际应用带来不利的影响，如控制电流的动态范围是否会减小等，因此，本文拟对磁性材料的B—H曲线的非线性影响做一定的分析和研究，以期找出解决的方法来尽可能满足主动磁悬浮支承技术在数控机床中应用的要求。本文首先分析研究了磁悬浮支承系统的基本工作原理，并在此基础上，分析和讨论了磁悬浮支承系统对功率放大器的要求，提出了适合不同类型磁悬浮支承系统的功率放大器设计方案。本文还分析、研究和实施了可用于旋转支承(电主轴)及平移支承(导轨或平台)的线性功率放大器。同时，分析、研究并实施了可用于旋转支承的开关功率放大器。其后，针对实验中发现的问题，总结和分析后，提出了一种智能型非线性增益开关功率放大器(简称非线性功放)的构想，以期专门针对磁性材料的非线性问题，从而解决磁悬浮系统中难于解决的关键问题——非线性影响问题。非线性功放的主要特征是在特殊设计的程序控制下能够实现“根据磁性材料的非线性特性自动调整功放的增益”的作用，从而消除系统中这方面的非线性的影响。本文的主要工作及贡献在于：以863计划项目的研究内容为目标，完成适用于相关样机的磁悬浮支承系统的功率放大器的分析、研究、设计和调试工作，并建立了相关的分析和设计理论和方法；提出了一种新颖的非线性功放的设计思想，期望这种功率放大器具有一定智能化，可对磁悬浮支承系统中由于铁磁材料引起的非线性问题进行有效补偿，其构思对实现其他类似系统的智能化有一定的借鉴和参考作用。更多还原

【Abstract】 The power amplifier of the magnetic levitation supporting system is studied mainly in the paper, including of the principle、the method of design and the technology of application, which is applied specially in the upscale CNC, for example the high-speed and high-precision electronic principal axis of machine (rotary bearing) and high-precision and high-speed plane (the guide of machine) (plane bearing).As to an active magnetic levitation system, the active magnetic levitation theory and supporting technology are the core theory and technology. According to the hardware, which consists of four factors chiefly: Place sensor and examination, signal control and modulate, power source and power amplifier, bearing and rotor. The problem existing in the power amplifier is analyzed and researched before the technology of controller and theory of power amplifier are discussed in the paper, thereby, the feasible scheme for resolving problem is proposed. Including of the analogy power amplifier of magnetic levitation bearing plane system which is—resolving the nonlinear problem to improve the rang of stability by "intelligent power amplifier". Finally, the correlation conclusion is gained by experimental data of Chinese 863 plan item—"the magnetic levitation bearing of upscale numerical control machine " (the item number: Experimental data2001AA423310).In the active magnetic levitation system, the steady suspend force is gained by regulating electric current of field coil in the part of the supporting body, Whose performance is close correlative with power amplifier. Usually, the gap between the supporting body and supported body is changing with the high-speed movement of supported body. The electric current of field coil is regulated according to the real-time position of being supported and the aim of steady levitation and dependable work is achieved. Hence, the power amplifier of the active magnetic levitation system is the key components to decide the performance of the magnetic levitation supporting and also is the core technology which is attentioned by researcher. In the active magnetic levitation system presently, there are two kinds of prevalent power amplifiers: the analogy power amplifier and the switch power amplifier. Although above two kinds are applied universally by more specialists, the nonlinearity of magnetic material makes the defect of less dynamic range arise in the actually application, which cause the development of magnetic suspension technology is not satisfactory. The nonlinear switch power amplifier which is proposed by this Dissertation is specially aimed at nonlinear problem of magnetic material, accordingly, which resolve the difficult and key problem of the magnetic levitation system—the problem of nonlinear effect.The switch amplifier works in state of on-off by switching characteristic of transistor. Thereby the power loss and heating etc of the switch amplifier are solved some degree, The nonlinear switch power amplifier is in the person of intelligentize for the switch amplifier. It will automatic regulate the gain of the switch power amplifier to remove the nonlinear effect according to the nonlinearity of magnetic material.In the nonlinear switch power amplifier, there are two kinds of methods to regulating directly the gain of the switch power amplifier: one is to control directly the on time and the off time to change the electric current of electro-Magnetic coil, which is called the Pulse width modulating technology, also is called PWM technology, the other is the fixed on-off time, regulating the coil current by change voltage, which is called voltage modulating technology. One of commons above is the transistor working in the switch state of high frequency.The main significance of the paper rests with: it proposes the design idea of a kind of novel intelligent power amplifier, and establishes the basic theory and method of design, which causes this kind of power amplifier compensate with the nonlinear magnetic permeability of elector-magnet core and regulate power voltage real-time according to real require. Uniting the numerical control technology and the power amplifier-technology and switch power technology. It realizes intelligence, miniaturization, high efficiency and large power.更多还原