A Numerical Calculation Model of Multi-Magnet-Array and 8-Shaped Null-Flux Coil for Permanent Magnet EDS Vehicle System

Inspired by the superconducting electrodynamic suspension (EDS) system in Japan, a new permanent magnet (PM) EDS system combining PM and 8-shaped null-flux coils has emerged in recent years. In general, the structure of a single PM was used as the onboard magnet. This single magnet structure is difficult to further optimize the core magnetic field resource of the EDS system. Facing this issue, we proposed a PM EDS system combining a Halbach PM array (HPMA) with good magnetic collecting capability and the 8-shaped null-flux coils. Furthermore, we established a numerical model for this new HPMA EDS system. The core of the calculation method is to discretize each PM in the HPMA into a coil group. By calculating the mutual inductance between the equivalent coil groups and the null-flux coils, the interaction electromagnetic force is obtained. In order to verify the correctness of our numerical model, the calculation results of the finite-element method (FEM) simulation model are compared with those of the numerical model. The results of two models are basically consistent. It shows that the numerical calculation model has high accuracy. On this basis, the effects of various parameters on three main electromagnetic forces are studied to better explore the application characteristics of the HPMA EDS system. To sum up, this established numerical model can effectively avoid the calculation error caused by the edge effect of the discontinuous magnet array. It provides an accurate calculation method for the optimization of the EDS system combining the PM array and the null-flux coils.