Analysis and Experiment of the Operating Capability of Low-speed Single-sided Linear Induction Motor

Abstract

This study presents some results of the analysis and experiments conducted for the operating capability of a linear induction motor (LIM) for moving a transfer vehicle of a high-speed high-tech container inspection system installed at ports. Such a container inspection system uses radiation to inspect all cargo inside without opening the container. The LIM is mounted to a transport vehicle for the container inspection system, and the transport vehicle moves through the system using radiation at a precise speed. Accordingly, constancy of speed and precise control are necessary for the vehicle. The LIM can move in a straight line without mechanical converting devices, and a system in linear motion needs no mechanical converting devices like cranks or gears. For this reason, such a system has good overall efficiency. On the other hand, an inevitable large air gap and the end effect necessarily generate both distortion of the thrust distribution anddegradation of the power factor. Therefore, in this study, a finite element method (FEM) analysis was conducted to examine precisely the operating capability of a designed LIM and suggest a control method for minimizing the disadvantages of the LIM. Among the results of FEM analysis, a curve of maximum efficiency according to slip was re?ected in a control algorithm. Operation with the variable slip frequency was found to reduce energy consumption.