基于FPGA的高可靠反作用飞轮控制算法研究

反作用飞轮是卫星姿态控制系统的执行部件,提高小卫星飞轮系统的可靠性及控制精度具有重要的意义.提出了基于现场可编程门阵列(FPGA)的高可靠反作用飞轮控制算法,首先介绍了反作用飞轮系统原理,分析得出FLASH型FPGA的高可靠性能,然后利用Verilog HDL语言编写浮点运算单元,并设计分段PI控制器.实验结果显示,速度响应从静止至6 000r/min耗时10s,超调量小于2r/min,稳态控制精度小于0.5r/min,验证了反作用飞轮系统设计的合理性,能够满足反作用飞轮的设计要求,进而可提高小卫星姿态控制精度.     

高温超导磁悬浮轴承的发展现状及前景

第二类高温超导体的磁通钉扎效应使得超导体在外加磁场中无需主动控制而能稳定悬浮。利用这种无源自稳定悬浮特性,高温超导磁悬浮轴承可以实现部件之间无机械摩擦的高速相对运动,在旋转机械、飞轮储能和交通运输等方面展现出了良好的应用前景。近年来,高温超导磁悬浮轴承的发展在世界范围内取得了令人瞩目的成就,轴承的设计思想、结构和应用环境都得到了相应的拓展。从结构特征角度综述了近年来国内外超导磁悬浮轴承样机的发展现状,重点介绍了西安交通大学的超导磁液复合轴承结构及其在液体火箭中的应用方案;结合该领域的研究现状探讨了超导磁悬浮轴承有待研究的问题和应用前景,指出超导轴承应向复合支撑方向发展以利于推进应用。     

减少阻力的MEMS初始位置定位机构设计与性能分析

根据微机电系统（MEMS）加工工艺特点和初始位置定位机构的设计要求,设计了两种MEMS初始位置定位机构的结构方案.通过力学分析,求出了定位机构解除定位所需要克服的阻力计算公式,用ANSYS仿真验证了其正确性.根据满足系统性能要求和利于装配两者均衡的原则,对两种定位机构的设计方案进行了对比研究,选择能减少阻力的MEMS初始位置定位机构.采用MEMS工艺中的LIGA工艺加工出初始位置定位机构.用VDS92-1430离心实验机分别加速到3 000 r/min、5 000 r/min、8 000 r/min和12 000 r/min进行离心实验.实验结果表明,设计的MEMS初始位置定位机构能正常工作,性能达到了设计要求.     

滑动轴承-转子系统油膜失稳参数影响分析

该文以单跨双盘转子系统为研究对象,针对滑动轴承在高转速时容易出现的油膜失稳问题,建立了考虑陀螺影响的转子系统集中质量模型,含油石墨轴承和滑动轴承分别采用弹簧-阻尼模型和短轴承非线性油膜力模型。在给定转速下考虑两种不同载荷工况（工况1,2分别表示两圆盘偏心同向和反向）,分析了转子的偏心距、轴承间隙、润滑油黏度、轴承长径比对系统振幅的影响。研究结果表明：工况1出现第1阶油膜失稳,工况2同时出现第1阶和第2阶油膜失稳;各参数在低转速(3200 r/min)时工况1和2系统振幅变化规律基本一致;在较高转速(5000 r/min和10000 r/min)时,系统振幅在工况2的情况下较工况1大;在高转速(13000 r/min)时,两种工况下系统振幅都存在较多突变点。     

轮缘驱动式姿控飞轮电机设计

为了提高小卫星用姿控飞轮的转动惯量/质量比,实现飞轮调姿系统的轻量化,设计了一种飞轮用永磁无刷直流电机.根据电机磁路,推导了磁钢尺寸与最大磁能积的关系;采用有限元法分析了磁路参数对飞轮性能的影响;针对飞轮电机大气隙、大径长比的结构特点,给出了气隙磁通密度的计算方法;建立了绕组参数与电机额定数据间的关系;仿真分析了电机性能.通过对一台最高转速为6 000 r/min、角动量为5 Nms的飞轮电机样机进行实验验证,得出最大设计误差为65%,证明了设计方法的正确性.     

电磁悬浮飞轮转子系统的模态解耦控制

基于电磁悬浮飞轮转子系统的数学模型,首先提出了一种在高速下能够使电磁悬浮飞轮转子系统保持稳定运行的模态解耦控制方法,然后对这种方法的解耦效果以及控制的有效性进行了仿真分析,并与传统分散PD控制的性能进行了比较。结果表明提出的模态解耦控制方法可以实现对电磁轴承飞轮转子系统的转动模态和平动模态间的解耦,以达到对各个模态的刚度和阻尼进行独立调节,使电磁悬浮飞轮转子系统具有更好的动态性能和更强的抗干扰能力的目的。     

飞轮储能系统转子动力学理论与试验研究

对永磁－机械动压轴承混合支承式飞轮储能系统的转子动力学问题进行研究。在推导出系统各部件的动能、势能和耗散函数的基础上，运用拉格朗日方法建立飞轮转子支承系统的运动微分方程，并用状态向量法求解。基于这一理论方法，对正在研制的储能量为0．3kWh飞轮系统进行动力学数值仿真。建立了飞轮储能系统的试验装置，研制了用于上、下支承的新型油阻尼器，完成了飞轮转子动力学的试验研究。研究表明，飞轮系统能顺利地实现在0－48，000r/min工作转速范围内的稳定运转，且动力学理论仿真与试验结果一致性较好。     

新型磁悬浮转子系统的专家PID控制研究

介绍一种新型磁悬浮轴承的工作原理,并且利用动力学和电磁学原理建立磁悬浮轴承系统的数学模型,讨论了刚度阻尼和控制系统的关系,通过此关系确定了常规PID的控制参数。利用常规PID的3个参数作为专家PID控制器的初始参数设计了专家PID控制器,并在磁悬浮轴承平台上进行了实验。实验结果证明此新型磁悬浮轴承控制系统在专家PID控制器的作用下能够快速、稳定悬浮,性能良好。     

磁悬浮分子泵转子振动抑制研究

磁悬浮分子泵具有工作转速高、转子极转动惯量大等特点,针对磁悬浮分子泵转子在升速过程中出现的弯曲模态振动以及涡动模态振动,提出了一种基于滤波交叉反馈与陷波器的大转动惯量磁悬浮转子控制方法。建立磁悬浮轴承-大转动惯量刚性转子系统数学模型,求解得出转子涡动模态频率,根据该模型分析了滤波交叉反馈控制器对涡动模态振动的抑制效果,并且设计了陷波器用于抑制不同转速下的转子弯曲模态振动。试验结果表明,磁悬浮分子泵稳定升速至工作转速18 000 r/min,转子振动位移为35μm,弯曲模态振动以及涡动模态振动得到了有效抑制。     

三瓦双向箔片轴承-高速电机转子系统动力学研究

以10 kW,120000 r/min的超高速永磁同步电机为实验样机,对三瓦双向箔片轴承-电机转子系统动力学行为进行实验研究。分析了三瓦双向箔片轴承的承载特点,在对轴承刚度和阻尼系数适当简化的基础上,计算了弹性支撑时的转子锥动模态频率和平动模态频率。在样机上进行了30000 r/min,60000 r/min的升速实验和90000 r/min的自由降速实验。实验表明:转子的起飞转速约为4000 r/min,当转子工作在90000 r/min时,伴随着强烈的亚同步涡动频率,而且该亚同步涡动频率完全是由轴承-转子系统本身所引起。结果显示三瓦双向箔片轴承-转子系统具有较好的稳定性,该理论分析和实验结果为超高速永磁电机轴系设计和动力学分析提供了参考。     

Design of an energy storage flywheel system using permanent magnet bearing (PMB) and superconducting magnetic bearing (SMB)

We propose a new energy storage flywheel system using a superconducting magnetic bearing (SMB) and a permanent magnet bearing (PMB). The superconducting magnetic bearing (SMB) suppresses the vibrations of the flywheel rotor. And the permanent magnet bearing (PMB) passively controls the rotor position. The energy storage flywheel system is characterized by using the two different type magnetic bearings of permanent magnet bearing (PMB) and superconducting magnetic bearing (SMB). This paper, discusses the design of the permanent magnet bearing (PMB) and the dynamics of the new energy storage flywheel system.     

水润滑轴承水膜压力无线监测节点供电方法研究

针对水润滑轴承水膜压力无线监测节点的供电问题,提出一种旋转能量收集方法并设计能量收集装置。旋转能量收集方法应用永磁发电机将转轴旋转产生的机械能转化为电能,并由能量收集装置(整流、降压、充电管理电路与锂电池)将电能进行转换与存储后为节点在线供电。首先对能量收集装置中的各电路进行仿真,然后建立节点能量模型并对节点能耗进行分析,最后进行旋转能量收集试验。研究结果表明:轴转速是影响能量收集效果的主要因素,转速为1200 r/min时,锂电池充电时间低于节点工作时间,充电过程中电池电能逐渐变大,电压逐渐上升,但进入恒压阶段后充电功率逐渐降低,转速1200 r/min比1000 r/min条件下充电效果更加显著。     

Designs and analyses of flywheel energy storage systems using high-Tc superconductor bearings

A horizontal axle-type flywheel energy storage system was manufactured using high-T_c superconductor bearings. The system running in a vacuum chamber mainly consists of a composite flywheel rotor, superconductor bearings, a motor/generator and its controller. The present system was designed to have an energy storage capacity of 440 W h at its operating speed of 40,000 rpm, which is way above two rigid body mode critical speeds. Rotordynamic analysis was performed on this system. Another flywheel system with vertical axis was conceptualized, which uses a hybrid superconductor bearing set to carry the wheel part load. The models for permanent magnet parts of the bearing set were designed using numerical magnetostatic analysis tool. The vertical magnetic force characteristics of the bearing set were experimentally measured. These results were discussed in regard of application to the flywheel system with a passive hybrid superconductor bearing set.     

A New Structure for Permanent-Magnet-Biased Axial Hybrid Magnetic Bearings

We propose a new structure for a permanent-magnet-biased axial hybrid magnetic bearing. Starting with the inner air gap and the outer air gap of conventional axial magnetic bearings, we first construct a novel air gap between the permanent magnet and the outer housing, which we call the second air gap, separating the bias flux paths from the control flux paths. As a result, the control flux paths will have lower reluctance, and the power loss of the axial magnetic bearing will be lower. Next, we modeled this axial hybrid magnetic bearing and analyzed it using the equivalent magnetic circuit method, 2-D finite element method (FEM), and 3-D FEM. We have designed and assembled an axial hybrid magnetic bearing prototype for a reaction flywheel system with angular momentum of 15 $hbox{N}!cdot!hbox{m}!cdot!hbox{s}$ at a speed of 5000 r/min. The theoretical analysis and the prototype experiments show such advantages as simple structure, good force current and force displacement, and high operating reliability.      

Basic design and characteristics study of a double-axial superconducting magnetic bearing system

Under the background of upgrading energy crisis, a double-axial superconducting magnetic bearing (SMB) system was designed and fabricated for a flywheel energy storage system (FESS) model to demonstrate high temperature superconducting (HTS) energy-saving technologies. In order to levitate and stabilize the shaft sufficiently, the static levitation force and lateral force between high temperature superconductor (HTSC) stator and permanent magnet (PM) rotors in two different sizes were checked. Based on the stable levitation, the dynamic characteristics of the SMB system were also investigated by the excitation experiments. The running experiments show that in the case of a driving motor the shaft can stably rotate along the central axis without any contact, while intensified vibration is also observed near two resonance rotational speeds. These results have been applied to construct and operate the FESS model using the SMB system.     

旋磁激励式圆形压电振子发电机

为满足旋转机构监测系统自供电需求,设计旋磁激励式圆形压电振子发电机,并着重研究磁铁尺寸、磁铁间距、压电振子厚度等对压电振子一次受激产生的最大输出电压及总能量的影响规律。结果表明,其它条件确定时,增加磁铁尺度或减小磁铁间距均可有效提高发电机输出电压及有效速带宽度。试验获得输出电压大于12 V的转速范围为100~2 850 r/min。压电振子厚度对输出电压及总发电量均有较大影响,低转速时采用薄压电振子、高转速时采用厚压电振子有助于提高发、供电能力。0.2 mm、0.4 mm、0.6 mm厚压电振子最佳转速分别为707.5 r/min、1 301.8 r/min、2 490.4r/min,0.2 mm厚压电振子一次受激产生的电能/功率分别为0.4 mm、0.6 mm压电振子的3.1/1.7倍、6.4/2.0倍。以输出5 V供电电压为例,912 r/min时0.4 mm厚压电振子输出电能为0.6 mm厚压电振子的5倍,1710 r/min时0.6 mm厚压电振子的输出电能为0.4 mm压电振子的1.7倍。     

Electrical Design of a 17 MW Class HTS Motor for Ship Propulsion

A superconducting motor shows several advantages, such as smaller size and higher efficiency, over a conventional motor, especially utilized in ship propulsion applications. However, the size reduction merit appears for large capacity, more than several MW. We develop a large capacity synchronous motor with a rotating high-temperature superconducting (HTS) coil, that is aimed to be utilized for ship propulsion, so it has a low rotating speed of about 200 rpm. The ship propulsion motor must generate high electromagnetic torque instead of low speed. Therefore, the rotor (field) coils have to generate a large magnetic flux that results in a large amount of expensive HTS conductor for the field coil. In this paper a 17 MW HTS motor for ship propulsion is designed with a cost-effective method because the HTS conductor cost is a critical factor in the construction of an HTS motor. Unlike conventional rotating machines, the superconducting motor consists of an iron-coreless structure. Most conventional motors can be designed with small error based on two-dimensional magnetic field analysis. However, the superconducting motor shows an even larger error between the two- and three-dimensional based designs. Thus, in order to improve the design accuracy, we have calculated the back electromotive force (EMF) using 3D magnetic field analysis. An output performance evaluation has also been carried out to obtain a design with higher efficiency.     

200kW/180MJ飞轮储能系统转子有限元分析与实验分析

为解决电网系统载荷波动大的问题,研制了200kW/180MJ飞轮储能系统实现动力调峰运行。采用有限元法对飞轮轴系进行建模与仿真,计算出飞轮转子临界转速、振型;并对以机械轴承为支撑的飞轮转子进行模态及谐波响应分析;进行多次飞轮升降速全周期检测,记录飞轮运行过程的幅频特性,进行对比分析。飞轮储能系统运行良好,未产生摩擦,振动幅度最大为1.6mm, 小于设计空隙3mm。     

Driving Mechanism of a Superconducting Magnetic Bearing System

Driving the rotor of a superconducting magnetic bearing without mechanical contact in the optimum conditions is an important task for high operational speeds. For this reason, an alternative eddy current mechanism is proposed to drive the rotor by means of magnetism with a speed higher than that of the driver. The designed driving system provides strong and stable magnetic coupling between the relatively rotating parts. The drag and lift forces between the rotor and driver disc are discussed by considering various conditions, such as the rotor configurations and the saturation of the magnetic field within the conducting material. The overall results indicate that the designed electromechanical driving system has potential solutions for the various applications for magnetic bearings from the effective driving mechanism point of view.