Fast and Precise Calculation of Mutual Inductance for Electrodynamic Suspension: Methodology and Validation

The mutual inductance is the core parameter of electrodynamic suspension (EDS) as it couples the onboard coils and ground coils to realize the stable suspension. The precise and efficient calculation of mutual inductance is therefore of great significance to understand and optimize the characteristics of EDS train, which has achieved a manned speed in excess of 600 km/h. In this paper, we proposed a calculation method of mutual inductance, considering the geometrical details of coils and the attitude of bogie, by means of the 3-D discretization of coils and the spatial coordinate transformation of discrete units. Based on this methodology, the analytical model was established, and the dependence of computation time and precision on the discretization degree is intensively discussed. Afterwards, the finite element analysis (FEA) was adopted to check the accuracy and effectiveness of the proposed methodology. Compared with FEA, the computation time has been reduced by 97% with accuracy reserved. Finally, a testing platform was constructed to further verify the availability of the proposed model. In summary, the proposed methodology can realize efficient calculation of mutual inductance in consideration of more realistic situations, providing an invaluable tool for the complex studies of superconducting EDS train.