Calculation and Optimization of High-Temperature Superconducting Levitation by a Vector Potential Method

We have theoretically established and experimentally validated a vector potential method for calculating the magnetic forces of high-temperature superconductor (HTS) subject to nonuniform magnetic fields generated by a permanent-magnet guideway (PMG). The highlight of the proposed method beyond the traditional approaches is that we introduced an auxiliary variable to represent both the magnetic vector potential and the electric scalar potential, which makes the calculation of superconducting levitation in 2-D space very efficient. By using the time-step finite-element technique to perform the spatial and temporal discretizations, the proposed mathematical model was numerically implemented and validated in a comprehensive manner by the measured data as well as the calculated data with other method. Enabled by the efficiency and robustness of the proposed method, we further incorporated this method into a genetic algorithm, and developed an intelligent scheme for optimizing the HTS maglev transportation system to realize a cost-efficient design. Using the maglev system, with one HTS levitated over a Halbach-derived PMG as a representative, we finally carried out a set of optimization studies to understand how the working condition and geometrical and material characteristics of the HTS affect its achievable levitation capability at different constraints of the cross-sectional area of PMG.