Design of a Slot-Spaced Permanent Magnet Linear Alternator Based on Numerical Analysis

Abstract

Linear alternators work seamlessly with Free-Piston Stirling Engines (FPSE) in the energy conversion process. This research concentrates on the design and development of a tubular slot-spaced Permanent Magnet Linear Alternator (PMLA) to be coupled with the FPSE. In an attempt to increase the power density of the machine over conventional PMLAs, a slot space is added to reduce the total mass of the stator and a parametrical study is carried out for the same. Numerically analyzing the fundamental parameters such as change of stator and magnet materials, and operating conditions frequency and stroke length. The effects of slotting are studied to understand the skinning effects on the tooth and the performance variation of the machine. A modified model is obtained to surpass 100 W from the numerical analysis of the parametric variations. Putting the machine to extreme limitations, the study conducted upon variations of parameters obtained a stable maximum power density of 186 W/kg and produced a power of 921 W for the designed PMLA. The study outlines the variation seen in the performance of the machine in such diverse conditions they go through during their life cycle.

Effect of Nonlinear Spring Characteristics on the Efficiency of Free-Piston Engine Generator

“…The linear machine was analyzed using the finite-element method with JMAG-Designer to set the parameter values. A tumbler-type linear motor, which is more reliable than the flat type, was used for the linear motor [28]. A Halbach arrangement was used for the permanent magnets in the mover to improve the output density.…”