Electromagnetic Characteristics Analysis and Thrust Fluctuation Optimization in Integrated Propulsion, Levitation, and Guidance Systems

Compared with typical superconducting (SC) electrodynamic suspension systems, SC electrodynamic suspension systems with propulsion, levitation, and guidance (PLG) are of great significance for reducing construction costs. In this article, an accurate model is developed to analyze the effects of electromagnetic forces on the 3-D electromagnetic force, electromagnetic torque, and electromagnetic stiffness when the onboard SC coil of a PLG system undergoes a deflection motion. The current compensation method is used to suppress the electromagnetic force ripples to improve the operating performance of the PLG system. First, the structure and operation principle of the PLG system is introduced, and second, the expressions of the three-way electromagnetic force, three-way torsional moment, and three-way torsional stiffness are given based on the imaginary displacement and equivalent circuit method. Then, the force and stiffness characteristics at different turning angles are analyzed, and the model's validity is verified by comparing it with the experimental data of the Miyazaki line. Finally, a controller based on current compensation for force ripple suppression is designed, and the force before and after control pair optimization is compared by simulation. The optimization scheme shows that the current compensation method reduces the force fluctuation and thus improves the performance of the PLG system.