LINEAR CONVEYER SYSTEM USING SELF-SENSING ACTIVE MAGNETIC BEARINGS

(1)用几何方法研究了自感知磁悬浮轴承的去噪问题。处理了两种类型的扰动，静态负载和正弦扰动(转子不平衡)。结果表明，在静态负载下可以实现虚拟零功率运行，同时可以补偿周期性扰动。(2)为降低成本，提出将自感知磁悬浮轴承应用于直线载体系统。(3)由于实心电磁铁的制造成本低，因此对实心电磁铁磁悬浮系统的自感知磁悬浮进行了理论和实验研究。(4)当采用实心磁铁时，磁铁内部涡流的影响在控制器的设计中必须考虑，因为它会引起磁通的相当大的时滞。引入了一个新的变量来代替线圈电流来描述实心磁悬浮轴承的动态特性。分析表明，在仅检测线圈电压和电流的情况下，采用新的状态变量后的系统是可控和可观测的。这意味着在叠层磁悬浮轴承中使用的自感知悬浮方法是可以应用的。(5)建立了研究实芯电磁铁主动磁悬浮轴承自感知悬浮的实验装置。(6)观测到磁通对线圈电流有很大的滞后。(7)测量了控制器设计所需的参数。(8)测量结果表明，一些参数依赖于频率。这给采用实芯电磁铁的磁悬浮系统实现自感知悬浮带来了很大的困难。

(1) Distubance cancellation for the self-sensing magnetic bearings was investigated by using the geometric approach. Two types of disturbances were treated, static load and sinusoidal disturbance (rotor unbalance) . It was shown that virtual zero power operation was achieved under static load while periodic disturbances could be compensated.(2) The application of self-sensing active magnetic bearing (AMBs) to linear carrier systerns was proposed for cost reduction. The configuration of the proposed system was demonstrated.(3) Since solid-cored electromagnets also lead to low-cost production, the self-sensing magnetic suspension in AMBs with solid-cored electromagnets was studied both theoretically and experimentally.(4) When solid cored are used, the effects of the eddy currents flowing in the cores must be taken into account in designing the controller because they cause a considerable time lag of the flux in the magnet. A new variable was introduced instead of the coil current to represent the dynamics of the AMB with solid cores. The analysis showed that the system with the new state variables was controllable and observable even if only the coil voltage and current were detected. This means that the self-sensing suspension method used in an AMB with laminated cores can be applied. (5) An experimental setup was built for studying the self-sensing suspension in the active magnetic bearings with solid-cored electromagnets.(6) A large time lag of the flux to the coil current was observed.(7) The parameters necessary for designing the controller were measured.(8) The measurements results showed that some of the parameters depended frequency. It lead to great difficulty in realizing self-sensing suspension in AMBs with solid-cored electromagnets.