Design of geometric parameters of a double-sided linear induction motor with ladder secondary and a consideration for reducing cogging force

In this paper, design of the physical of double-sided linear induction motor with ladder secondary is presented. It has aim to obtain the high-precision of DSLIM for the linear slow speed applications. One of limiting factor for precision linear movement is cogging force. The efforts in reducing the cogging action in rotary induction motor has been conducted very well. However, the cogging force reduction in the DSLIM with ladder secondary has not been done before. The DSLIM provide a great advantages for LIM-driven wheel vehicles for specific applications, for example vehicles that are used in over short distances, e.g. at planned stop, switches, or slopes or linear feed axes of machine tools. The disadvantage for very low applications is the existence of cogging forces that can cause the precision-decreasing of the linear movement. The design for reducing cogging force refers to storage magnetic energy variation in the air gap. At first, effects of ratio slot pitch between in the moving and stationary parts over the storage magnetic energy have been investigated and produced a new structure results of DSLIM. Secondly the winding structures variation in slots of moving part which it can make cogging force between tooth cancel each other. The design results has been verified using FEM (Finite Element Method) and an experimental verification.