Iron Loss and Inductance Analysis Considering Magnetic Nonlinearity in Multi-Segmented Plate Permanent Magnet Linear Motor

In multi-segmented linear motor magnetic field includes coupling and uncoupling parts, so electromagnetic parameter characteristics considering magnetic nonlinearity are different from that of rotary or short-stator counterparts, especially about parameters variation at transition. In this paper magnetic field characteristics of multi-segmented permanent magnet linear motor are analyzed by combined simulation model, and then we evaluate iron loss and inductance in equivalent circuit taking switching harmonics into account. Meanwhile, due to the action of PM magnetic field at transition, parameters involved with the length ratio of mover to one segment show distinct changes. We present a comparative analysis for multi-segmented motor equipped with distributed and concentrated windings. Based on two types of fabricated prototypes, experimental results validate the analysis results.

I. Introduction

The long-stator linear motors have been deemed as the favorable choice for intercity transportation system where high speed and acceleration are typically required, and synchronous motors are used to avoid the transfer of traction energy to the vehicles [1], [2]. Generally the designs of long stator are widely adopted modular armature segments, which are easy to assemble and maintain. If the stator segments associate with the fault, it can be quickly and easily replaced with a new healthy one.