Study on Electromagnetic Relationship and Dynamic Characteristics of Superconducting Electrodynamic Maglev Train on Curved Track

This study considers an electrodynamic maglev train of the MLX01 type as the research object. Equivalent circuit models of levitation/guidance were established, and forces in different directions were solved using the energy method. A field-circuit-motion coupling numerical model of a single bogie and a ground coil was established. Based on the field-circuit-motion coupling model, the various electromagnetic relationship of maglev train on curved track was analyzed. The law of the electromagnetic spring coefficient and the internal mechanism under different electromagnetic parameters was explored. Considering the coupling characteristics between the electromagnetic forces, the characteristics of the levitation force and guidance force under different standard air gaps were analyzed, and a numerical fitting analysis was performed. On this basis, the laws of levitation force and guidance force with levitation displacement and guidance displacement, as well as the characteristics of drag force with operation speed under different standard air gaps, were studied. Meanwhile, the characteristics of the guidance-drag ratio and levitation-drag ratio were analyzed. A dynamic model with 20 degrees of freedom was established based on the analysis of the geometric model of the maglev train. Taking the track irregularity as the external excitation source of the bogie, the dynamic characteristics of the bogie and vehicle body under different standard air gaps and speeds were analyzed. The effects of different suspension damping and stiffness coefficients on the vibration characteristics of a vehicle body were studied. This provides important theoretical and data support for design and dynamic analysis of superconducting electrodynamic maglev trains.

I. Introduction

Owing to their small turning radius and strong climbing ability, high-speed maglev trains have become an ideal high-speed and ultra-high-speed transport system in the 21st century [1], [2]. At present, the relatively mature maglev train technology includes electric magnetic suspension (EMS) and electric dynamic suspension (EDS) [3], [4]. The suspension/ guidance system of the EMS adopts active control, and can realize stable levitation under static conditions. EDS has a large levitation air gap (100 mm), and as a repulsion system, it is mechanically self-stable without a complex control system [5], [6], [7]. EDS is self-stable levitation and guidance during train operation. The passive electromagnetic damping between SC (superconducting) coil and LG (levitation/ guidance) coil is very small, and the train is composed of light vehicle body and relatively heavy bogie structure [8], [9], [10]. Therefore, it is of great significance to analyze the characteristics of levitation/guidance and reveal the dynamic characteristics during train operation.