Study on the Levitation and Traction Characteristics of High-speed Maglev Trains Dragged by Five-phase Synchronous Linear Motors

In response to the demand for high-speed performance of normal conducting magnetic levitation trains, a five-phase linear synchronous motor is proposed as the traction and levitation system. On the basis of the long stator cogging structure of the traditional three-phase LSM, the widths of the main and final poles of the levitation electromagnet are increased to meet the principle of the long pitch of the kinetic poles; then the parameters of reactance, resistance and excitation electromotive force of the five-phase LSM are calculated according to the analytical method, and the equivalent circuit is established; finally, a two-dimensional model of the five-phase and three-phase LSMs is established in the finite element, and the traction and levitation characteristics of the five-phase LSM are calculated and analyzed. The results show that the five-phase LSM can provide more armature current under the same voltage as the three-phase LSM, which is beneficial to the thrust force; and the traction and suspension force of the five-phase LSM with the same excitation current are larger than those of the three-phase LSM under the same levitation air gap; the traction and levitation force of the five-phase LSM with the same levitation air gap are also larger than those of the three-phase LSM under the same excitation current. The above results show that the five-phase LSM has better traction and levitation characteristics than the three-phase LSM, and also has a higher speed boost range.