Performance analysis of a linear induction motor based on the finite element method

Single-sided linear induction motors (SLIMs) have been widely applied in transportation recently. For its cut-open magnet circuit along moving direction and different width between primary and secondary, it has longitudinal end effect and transversal edge effect, which bring some efflucence to its mutual inductance and secondary resistance. Furthermore, SLIM has normal force for its unsymmetrical structure in vertical direction, which is evident in large slip and current region so as to interfere the propulsion control schemes. According to these SLIM traits, this paper based on the finite element method employed by the commercial software ANSOFT has investigated SLIM transient thrust, normal force, air gap flux density distribution, where the thrust is verified by the measurement. The results indicate that the 2D model can provide comparatively reasonable prediction to the SLIM electromagnetic design and control schemes implementation.

I. Introduction

The SLIM drive system has the following merits compared with that propelled by the rotary induction motor (RIM): greater ability to exert thrust on the secondary without mechanical contacts, higher acceleration or deceleration, less wear of the wheels, smaller turn circle radius, and more flexible choice of road line. However, for its primary cut-open magnetic circuit, the SLIM suffers some inherent demerits, such as longitudinal end-effect, transversal edge-effect, and normal force, et al.