【作者】 崔东辉；

【导师】 徐龙祥；

【作者基本信息】 南京航空航天大学 ， 机械设计及理论， 2010， 博士

【摘要】 主动磁悬浮轴承正逐渐走出实验室,应用到实际的工业设备上。主动磁悬浮轴承由于没有机械磨损,工作寿命可以很长,具有比较高的可靠性。但是当把主动磁悬浮轴承用于某些对可靠性要求比较高的设备时,如磁悬浮多电发动机和采用主动磁悬浮轴承的核能发电设备,其可靠性仍然无法满足要求。因此如何进一步提高主动磁悬浮轴承的可靠性是目前国内外研究的热点。文中对高可靠磁悬浮轴承系统关键技术进行了研究。文中针对采用差动方式测量转子位移的主动磁悬浮轴承提出了两种故障位移传感器识别算法。文中研究了位移传感器探头故障与位移传感器输出及控制器输出之间的关系,分析了当不同探头发生故障时位移传感器输出和控制器输出的特征,在此基础上提出了基于自适应滤波和基于离散傅里叶变换两种探头故障检测及识别算法。文中对算法进行了仿真研究,并在一个五自由度主动磁悬浮轴承试验台上进行了试验研究,研究结果表明:无论转子在静态悬浮还是高速旋转时采用这两种算法均可以准确地检测到位移传感器故障并识别出故障位移传感器。文中在基于电流分配矩阵重构的基础上提出了基于坐标变换的执行器容错控制算法,并针对一个六极磁路耦合的径向磁悬浮轴承的五种故障模式进行了研究。文中分析并导出了每种故障模式相应的坐标变换矩阵和线圈重映射矩阵,对每种故障模式下转子的起浮特性和故障切换特性进行了仿真研究,并在一个两自由度磁悬浮轴承试验台上进行了试验研究。文中把基于坐标变换的位移传感器容错控制算法和基于坐标变换的执行器容错控制算法相结合提出了基于坐标变换的位移传感器和执行器容错控制算法,该容错控制算法能够容许位移传感器和执行器线圈同时出现故障而保证转子的稳定悬浮。文中采用MATLAB对该算法进行了仿真并在一个两自由度磁悬浮轴承试验台进行了试验研究,研究结果表明:采用该容错控制算法可以最多在一个位移传感器和三个执行器线圈同时故障情况下实现转子的稳定悬浮。文中针对安装三个位移传感器的径向磁悬浮轴承研究了基于坐标变换的位移传感器容错控制算法,采用MATLAB对该算法进行了仿真研究,并在一个两自由度磁悬浮轴承试验台上进行了试验研究。研究结果表明:采用该容错控制算法可以在任一位移传感器发生故障时实现转子的稳定悬浮。文中针对一个六极磁路耦合的径向磁悬浮轴承研究了基于电流分配矩阵重构的执行器容错控制算法,导出了该磁悬浮轴承在非故障状态和两种故障状态下的电流分配矩阵,对转子在三种状态下的起浮特性和故障切换特性进行了仿真研究,并在一个两自由度磁悬浮轴承试验台进行了试验研究,研究结果表明:采用该算法可以实现转子在故障状态下的稳定悬浮。文中研究了机械加工误差对主动磁悬浮轴承性能的影响。文中针对一种典型的五自由度主动磁悬浮轴承介绍了常见的机械误差形式,详细地分析了每种误差形式对主动磁悬浮轴承工作状态的影响机理及特征,建立了误差和主动磁悬浮轴承工作状态之间的定量关系,并将该研究成果用于检测主动磁悬浮轴承机械部分在加工和装配中存在的问题,以提高主动磁悬浮轴承机械部分的装配精度,提高主动磁悬浮轴承的性能。更多还原

【Abstract】 Active Magnetic Bearing (AMB) has gradually been applied to actual industrial area from laboratory. Nonexistent friction makes AMB own longer work life and high reliability compared to conventional bearings. However, the reliability still can not satisfy the requirements of some special equipment, such as more-electric gas turbine engines and nuclear generator equipped with AMB. Therefore, methods to enhance the reliability of AMB have recently been the research hotspots at home and abroad. Key technologies of AMB with high reliability are studied in the paper.Two displacement sensor failure diagnosis methods are presented according to the active magnetic bearing adopting differential method to measure the displacement of rotor. The relationship between the output signal of controller, the output of displacement sensors and the disturbed signal applied to displacement sensor probes is analyzed. Characteristics of displacement sensor’s output and controller’s output of the failed sensor are analyzed when different displacement sensor probe failed. Based on the principle, fault diagnosis methods for the displacement sensor probes based on adaptive filtering method and discrete Fourier transform are presented. The methods are firstly studied by simulation using MATLAB tool and then the experiments are made on a five degree of freedom active magnetic bearing test rig. The result shows that both of the methods can identify the fault of the displacement sensors when the rotor rotates at high speed and stays stationary.The coordinate transformation-based actuator fault-tolerant control algorithm on the basis of current distribution matrix reconstruction is presented. Aiming at the five failure modes of a six-core radial AMB with coupled magnetic path, the corresponding coordinate transformation matrix as well as the coil re-mapping matrix for each mode are derived. Suspending and failover characteristics of the rotor in each failure mode are simulated, and then the relative experiments are taken out on a two degree of freedom active magnetic bearing text rig.The displace sensors and actor fault-tolerant control method based on coordinate transformation is presented,which can ensure the stability of the rotor suspension in the condition that the sensors and the excitation coils fail at the same time. This algorithm is simulated using MATLAB and studied on a two degree of freedom active magnetic bearing text rig. The result shows that the fault-tolerant control algorithm can achieve the stability of the rotor suspension in the state that one displacement sensor and three excitation coils at most failed synchronously. The fault-tolerant control algorithm based on coordinate transformation of the radial magnetic bearing installed with three displacement sensors is studied and simulated using MATLAB. The experiment is also made on a two degree of freedom active magnetic bearing text rig. The result shows that the fault-tolerant control algorithm can achieve the stability of the rotor suspension in the state that any displacement sensor failed.The fault-tolerant control method based on current distribution matrix reconstruction is studied according to a six-core radial AMB with coupled magnetic path and distribution matrixes of normal state and two fault states are derived. Suspending and failover characteristics of the rotor in the three kinds of states are simulated, and then the relative experiments are carried out on a two degree of freedom active magnetic bearing text rig. The result shows that this fault-tolerant control method can achieve stable suspension in fault condition and can switch to normal station stably when the failure occurs.In the end, the influence of mechanical error on the performance of AMB is studied. Common mechanical errors of a classic 5-DOF AMB are introduced. The influence mechanism of each mechanical error on the working state of AMB is analyzed in detail. The relationship between machining errors and the working parameters of AMB is quantitatively analyzed. The results are used to identify the problems caused by cutting and assembling so that the assembly accuracy of mechanical part and the workability can be improved.更多还原