Design And Implemention Of EMS System Based On High Temperature Superconductor

High temperature superconducting materials have shown great advantages and broad prospects significance in strong electricity and superconducting electronics.Applying HTS wires to maglev train coils,instead of normal conducting copper or aluminum windings,can greatly reduce power consumption and the volume of the suspension system for the zero-resistance and small cross-sectional area character.The prevailing practice at home and abroad is conducting direct current in the superconducting wire to produce a constant magnetic field,in addition normal conductor parallel coils providing a varying magnetic field to maintain system stability.But this suspension system retains two systems,so that the whole system becomes complicated.To this end,this paper discusses feasibility and availability of stable suspension of the vehicle by controlling the superconducting coils' current directly.The biggest problems of controlling the superconducting coils' current directly are the quench problem and ac loss problem.Around these problems,this article built up a HTS experimental device and built up the dynamic model and three-dimensional finite element model,then analyzed the magnetic field distribution around the superconducting coil?the critical current and the suspension current impacts to the ac loss;On this basis,developed a performance index function of minimizing ac loss;Under the constraints of the performance index function,optimal designed the superconducting suspension control algorithms and parameters,thus ensuring stability of the suspension system and the maximum reduction ac loss.The results of simulation and experiments demonstrated the effectiveness of control algorithms.This paper described the design of the structure of HTS device firstly.Then analyzed quench causes of HTS coils based on quench character and introduced the parameters of the superconducting magnet stability,from the perspective of ac loss and suspended current change process summed up the critical current and thermal stability current,and designed experiments to test them.This paper went with electromagnetic field simulation of HTS device then.Then it built up Maxwell three-dimensional simulation model to analyze the influence of magnetic field on the superconducting coil in critical current.Then we analyzed the track's electromagnetic force,selected proper suspension stable point.Next there are HTS modeling and control algorithm designing.This paper established the dynamic model of HTS system and linearized model by using feedback linearization method.For HTS system it proposed suspension system's performance evaluation and loss performance indicators;built up Matlab simulation model,under the constraints of performance superconducting loss function minimization and dynamic performance function,this paper optimal designed the control algorithms and parameters.Then this paper proposed a mass adaptive control method to adjust the mass change accounting for diminishing load mass change influence to suspension system.Finally,we designed the hardware and software of HTS experiment system and we did the suspension experiments.We introduced the details of the hardware and software design,carried out experiments to verify the feasibility and controllability of HTS system in the HTS experiments system.