Research on Multiobjective Optimization of Long-Stator Synchronous Linear Motors Structure for EMS Maglev Train

The electro-magnetic suspension (EMS) high-speed maglev trains are currently the only commercially available high-speed magnetic suspension trains with advantages such as high efficiency and high speed. However, as the application and operation continue, the demand of usage can't be met by the existing operating speed. Therefore, it is inevitable to increase the speed of maglev trains. the structure of the existing long-stator linear synchronous motor (LSLSM) of the maglev train is designed according to the operating speed of 430 km/h. Therefore, its structure needs to be optimized for the operating conditions of 600 km/h and above. In this paper, firstly, the magnitude of propulsion force and suspension force, the magnitude of propulsion force and suspension force pulsation, and the suspension-to-weight ratio are taken as the optimization objectives, and then the weight factors are set according to the operating conditions of the maglev train respectively, and then Taguchi's method is used to design the orthogonal test scheme in combination with the signal/noise (S/N) ratio and the fuzzy theory. Finally, the optimization results are verified through finite element simulation comparison. The results show that: the magnitude of the propulsion force is increased by 5.22%, and the propulsion force suspension force fluctuation and propulsion force fluctuation are reduced by 38.66% and 30.48%, respectively; due to the optimization of the motor structure, the core of the LSLSM achieves a weight reduction of 32.06 kg, and the suspension-weight ratio is increased by 7.65%.