Analysis of permanent magnet type transverse flux linear motor by coupling 2D finite element method on 3D equivalent magnetic circuit network method

Permanent magnet (PM) type transverse flux linear motors (TFLMs) are electromagnetic devices which can develop directly powerful linear motion. The unique configuration makes the output power higher than longitudinal motors, but also it makes characteristic analyses difficult. This paper deals with an effective analysis of a PM type TFLM by coupling 2-dimensionaI finite element method (2D FEM) on 3D equivalent magnetic circuit network method (EMCN). 2D analysis by FEM is used to find so-called multipleratio, which is multiplied by 3D analysis results, and 3D EMCN is employed in magnetic field analysis to get the static thrust and parameters for system assessment such as flux linkage, coenergy, apparent inductance, and incremental inductance. The calculated results are verified by comparison with measurements.

I. Introduction

Linear motors are electromagnetic devices developing mechanical thrust without gear or rotary-to-linear converters. The advantages of linear motors include low noise, reduced operating cost, and increased flexibility of operation because of the gearless feature. Linear motors, however, have a few practical limitations. The major reason is the low power density due to the inherent large air gap [1]. For the application of linear motors to high power system, therefore, Permanent Magnet (PM) type Transverse Flux Linear Motors (TFLMs) can be considered because the motors can develop high magnetic thrust and reluctance thrust in relatively small air gap. There are several practical examples of TFLMs and their rotary counterparts in [2]–[5].