Design And Analysis On Suspension System Of Maglev Based On Superconductor

The traditional EMS maglev system has been successfully taken into practice because of the relatively reliable technology. But there are some disadvantages in the normal-conduct maglev system, such as, limited suspension gap, large power consumption, high requirement of rail precision, etc., which makes the hybrid suspension system become a new research hotspot. Based on the purpose of increasing suspension gap and lowering the power consumption of suspension, a magnetic suspension system is designed based on the HTS (High Temperature Suspension) technology in this dissertation; the design of the HTS electromagnet together with the suspension control algorithm are also discussed.The main content of this dissertation include:1. A new structure of bogie based on HTS technology is designed with regard to the engineering requirement; applying HTS technology, a HTS electromagnet is designed using Bi2223 silver sheathed superconducting tape. The electric and magnetic character of the HTS suspension system is studied in detail applying finite element analysis; the relationship among suspension gap, the current of superconducting coil, and the critical current is studied based on the superconducting character of HTS materials, which deduces the critical current of the HTS coil and the maximum suspension gap in the condition that the coil is superconducting. The power consumption of the HTS coil when suspending is also calculated, thus a G-M crycooler is chosen as the cooling system.2. The mathematical model of the superconducting single electromagnetic suspension system is established, and the controllability is studied. The traditional control method is based on the linearization of the nonlinear system near the equilibrium point, which may lead to the deterioration of the controller when coping with big perturbation, thus affects the stability of the system. With regard to this problem, a mass-based decoupling suspension controller is designed on the base of feedback linearization, and an observer is also established in order to observe the change of mass. The simulation shows that the observe tracks the change of mass rapidly, and using this control scheme, the anti-perturbation capability and the robust character can be greatly improved.3. A digital controlling system based on DSP is designed in order to realize the control algorithm. The algorithm is programmed, and a voltage-controlling current source is designed for the HTS suspension system.The works in this dissertation are faced to engineering application, which make a good reference to the design of HTS suspension system. Although the HTS suspension system designed in this dissertation seems more complex than the normal-conduct EMS suspension system, and costs a more difficult operation condition, it can realize greater suspension gap, reduce the suspension power consumption, thus decreases the costs of the guideway. With the quick development of HTS materials and the refrigeration technology, it is believed that the hybrid HTS maglev system would be widely appled.