Development and Testing of a Novel Cylindrical Permanent Magnet Linear Generator

Vernier hybrid machines (VHMs) are known for their simple salient translator structure and inherent magnetic gearing, making them a strong candidate for low-speed, high-force applications. As both the armature coils and the permanent magnets (PM) are mounted on the stator, linear versions of this machine are attractive for applications with a large stroke amplitude. In most configurations, single-sided or double-sided flat cross sections are utilized, giving a two-dimensional flux path. In this article, a cylindrical variant of the double-sided flat configuration is presented, where the flux path is now three dimensional. Three-dimensional finite-element analysis is used to design, analyze, and compare both flat and cylindrical topologies for a fixed PM mass and current density. Details and test results of a soft magnetic composite based laboratory prototype of the cylindrical VHM are given, which demonstrate the concept and validate the simulation results.