LINEAR CONVEYER SYSTEM USING SELF-SENSING ACTIVE MAGNETIC BEARINGS

(1)采用几何方法研究了自感磁轴承的距离消去问题。处理两种类型的干扰，静载荷和正弦干扰（转子不平衡）。结果表明，该系统在静负荷下可实现虚零功率运行，并可补偿周期性扰动。(2)提出了自感知主动磁轴承（AMBs）在线性载波系统中的应用，以降低成本。最后对系统的结构进行了验证。(3)由于实心电磁铁生产成本低，本文从理论和实验两方面研究了实心电磁铁AMBs中自感磁悬浮。(4)采用实心磁芯时，磁芯内涡流的影响在设计控制器时必须加以考虑，因为涡流会使磁体的磁通产生相当大的时滞。引入了一个新的变量来代替线圈电流来表示带实心磁芯的AMB的动态特性。分析表明，在只检测线圈电压和电流的情况下，采用新状态变量的系统是可控和可观察的。这意味着自传感悬架方法可以应用于具有层压芯的AMB。(5)建立了实心电磁铁主动磁轴承自传感悬架的实验装置。(6)观察到磁通对线圈电流有较大的时滞。(7)测量了设计控制器所需的参数。(8)测量结果表明，部分参数与频率有关。在实心电磁铁驱动下实现自感知悬架存在很大的困难。

(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.