The computation of mechanical dynamic characteristic in EMS-Maglev system by electro-mechanical equations coupled finite element analysis

Abstract

The paper describes a fast solving technique for the mechanical dynamic characteristic of electro-mechanical motional systems. Based on a sequence of finite element analysis, and a set of equivalent electrical circuit parameters extracted, the method incorporates electrical equation and vehicle's movement equation into state equations. Through test of an EMS-Maglev system, it reveals that the method gives reasonable results at very low computational costs comparing with transient finite element analysis. In electromagnetically levitated transport systems (EMS-Maglev), such as the German Transrapid, the propulsion is supplied by a Long-stator linear synchronous motor (LSM) of which the stator (armature) is fixed at all along the guide way and the moving poles with the excitation (levitation magnets) are on the vehicle. The dc exciting windings create main field and levitation forces. The armature windings of the LSM are energized by three-phase alternating voltage over a power supply section. And linear generator supplies the on-board electric power. Figure 1 shows the overall view of the EMS-Maglev transport system and the configuration of LSM longitudinal section together with the on-board linear generating system. The analysis of its mechanical dynamic characteristics is very important for the design of the configuration and the control system. Due to the complexity of the time-varying magnetic configuration, the external power supply of the LSM and the working status of linear generator, field-circuit coupled transient analysis is required. Conventionally, the time-stepping method is employed to analyze the dynamic characteristics of moving systems (1-3). Therefore, the determination of the instantaneous values requires the recurrent utilization of a FE solution. However this directly coupled FE method to analyze the dynamic characteristics is very time-consuming because the system matrix should be solved at each incremental time. In order to overcome this problem, a fast solving technique is presented for the analysis of mechanical dynamic characteristics of electromechanical motional system. Based on a