The Research And Test Of The AC Loss Of HTS Electro-magnetic Suspension

The electromagnet coil of traditional electromagnetic suspension system is normally conducting wire,which will lead to great resistance loss in continuous operation condition.High temperature superconducting(HTS)has the characteristic of non resistance in the DC case,but it will produce AC loss if the current is alternating.The current in the coil of the electromagnetic is dynamic regulating superimposed on a DC bias.In this paper,the characteristics of high temperature superconducting materials used for magnetic suspension are studied based on the analysis of AC loss from the dynamic regulation current.The main contents of this paper are as follows:Firstly,the spectrum characteristics of the suspending current of CMS-04 maglev train are studied according to the characteristics of the electromagnetic suspension structure.We present a preliminary prototype of a HTS Suspension test platform and analyze the mechanism of AC loss.A method for measuring the AC loss of HTS suspension is presented based on the characteristics of the AC loss.Secondly,a critical current testing system is established based on Lab VIEW.The critical current of the HTS coil is tested,the test data are fitted and analyzed to obtain the critical current of the superconducting coil.The critical current of the HTS coil under different suspension gap is analyzed using test data and FEM method.Then,the HTS coil is simplified to a two-dimensional superconducting tape section and the finite element simulation model is established based on critical current test data and E-J power law.The loss characteristics of HTS tape in steady current,sinusoidal wave current and suspending current are analyzed to obtain the loss trend with the changing current.And the influence of different superconducting materials on the AC loss is also simulated.At last,the AC loss of high temperature superconducting coil is tested by electrical method to get the loss curve of the coil in different current.The characteristics of AC losses in HTS suspension are analyzed and compared with common conductor.Then,the selection of working points in HTS suspension is studied,and the impact of the AC loss on the HTS suspension control system is analyzed.In this paper,aiming at the AC loss of HTS electromagnetic suspension system,the feasibility of superconducting tape used for magnetic levitation is verified by simulations and experiments.Research reveal that the AC loss is very small when HTS applied to the EMS system,and HTS can significantly reduce the power consumption of the entire suspension system compared to normal conductor,which provide a guidance for the design and application of HTS in EMS system.