Double-Sided Permanent Magnet Linear Motor Research Articles

A Novel Track Structure of Double-Sided Linear PM Synchronous Motor for Low Cost and High Force Density Applications

Conventional coreless linear permanent-magnet (PM) synchronous motors have been used commonly in various applications in industry. In this article, coreless double-sided PM linear motor design alternatives are proposed with a novel track structure with less magnets. A linear motor design with conventional coreless PM linear synchronous motor (PMLSM) is provided as a benchmark. Detailed 3-D finite-element analysis simulations for the proposed new track structures are presented with conventional linear motor design data. A thorough performance comparison is also presented. A prototype motor of a promising track design is built and tested. It is shown that the design data and test results are in good agreement, and the proposed alternative track design could be a decent low cost and relatively high force density solution for some applications.

Demagnetization Fault Detection for Double-Sided Permanent Magnet Linear Motor Based on Three-Line Magnetic Signal Signature Analysis

This article investigates a novel demagnetization fault detection method for double-sided permanent magnet synchronous linear motors (DS-PMSLM) that are applied in laser cutting machines. First, a finite-element analysis model of DS-PMSLM is built to preset different demagnetization faults of the permanent magnets (PMs). Second, magnetic intensity distribution signals in air gap region are selected as fault signal for the first time to detect demagnetization faults in DS-PMSLM. Three-line method coupled with self-designed connection structure is originally proposed to obtain and analyze three-line magnetic signals. Simulation comparison with back electromotive force signal validates that three-line magnetic signals are more effective to solve the problem for this double-sided structure PMSLM. Then, continuous wavelet transform (CWT) is innovatively introduced to conduct peak feature extraction for magnetic signals. Comparison experiments between CWT, direct locating method, and polynomial fitting method certify the superiority of CWT. By peak feature analysis, the positions, sides, and severity degrees of PMs' demagnetization faults can be detected accurately. Finally, a prototype is manufactured, and a Gauss meter experimental platform is established to verify the validity and advantages of this method.