Study on the Stability of Zero-Flux Superconducting Electro-Dynamic Suspension Systems With Electromagnetic Potential Energy Surface

The dynamic stability is crucial to successful operation and passenger comfort in zero-flux electric-dynamic suspension (EDS) systems. Usually, the stability problem is studied by a dynamic method where equations of motion are solved, with the electromagnetic interaction and the motion of the vehicle coupled in different levels. The dynamic studies provide information on operation strategies such as active or passive damping designs. In this work, the stability of the system is studied from another angle, where the vehicle body and bogie are taken as a whole and the stability is evaluated from the “potential energy surface” of the system. Although the system is not conservative, the difference between path integrals of electromagnetic force along different paths is small. For approximation, the stability is evaluated by taking the path integral as potential energy. Instead of dynamic stabilities, the method reveals the quasi-static stabilities. Instead of a damping strategy, the work is focused on the geometrical design parameters. The study is done with different system design parameters, which reveals that the height of the upper ground coil is one of the most important parameters that affect the lateral-roll coupled stability. The design principle is to have maximum mutual inductance between the on-board and upper ground coils, as well as maximum spatial derivative of the mutual inductance.