Structure and control design of levitation electromagnet for electromagnetic suspension medium-speed maglev train

Electromagnetic suspension is considered as a widely-used type of maglev train systems. It has been successfully used recently in Changsha Maglev Express (CME), China. Great research interests and engineering efforts have been focused on increasing the operation speed of such an environment-friendly low-speed maglev type to 200 km/h in order to meet the requirement of inter-city transportation, which has not been realized yet. However, at a higher speed, there is a considerable levitation force drop at the front of vehicles due to the pronounced eddy current effect. The electromagnet modules are more likely to saturate. An optimized electromagnet design is required for the medium-speed maglev train to achieve better levitation capability, weaker vibration, and more comfortable ride. Based on the actual parameters and operation data of CME, this paper uses the three-dimensional finite element analysis method to fully analyze the occurrence of magnetic saturation and its adverse effects. A novel structure design of electromagnet module coping with the problem of magnetic saturation is proposed to improve the levitation performance. The study also puts forward a three-controller system on the electromagnet module at the front of the vehicles which can effectively ease the imbalance of levitation forces.