Calculation and Optimization of Propulsion Force of a Real-Scale REBCO Magnet for EDS Train

Electrodynamic suspension (EDS) train has the unique advantages of excellent levitation and guidance stabilities, large levitation gap, and so on. All of these merits make it a promising candidate for the future ultra-high-speed transportations, in which the high-temperature superconducting (HTS) linearly synchronous driving motor (LSM) plays an important role because of the decrease of energy consumption of HTS magnet. This paper, which serves as a fundamental study on the HTS synchronous driving system of EDS train, is aimed to calculate the propulsion force of LSM and optimize the propulsion fluctuation. First, in order to define the operating current of LSM, the critical current of a real-scale REBCO coil was numerically estimated using the so-called T-A model. Second, based on the Neumann formula and virtual displacement method, an analytic model to estimate the propulsion force of LSM was established and verified by comparing results with a finite-element method (FEM) numerical model. Finally, by resorting to the validated analytic model, the geometric parameters of propulsion coil were optimized, and then using the optimal parameters, the maximum electromagnetic forces of LSM under different operating conditions of EDS train were calculated. It was found that the linearly driving system inherently keeps robust driving stability to the lateral and normal displacements.