Manufacturing and Characterization of Novel Multilayer Magnets for Electrical Machine Applications

This paper presents the potentialities of diverse kinds of permanent magnet materials in order to build and characterize multilayer magnets, as well as to investigate their prospective application in electrical machines. In particular, bonded magnet and hybrid magnet powders are used to build two-layer samples, which pave the way for constructing special electrical machines with complex magnetic structures, such as the variable flux permanent magnet machines. In this study, samples of innovative double-layer magnets are built through a single press and the following magnetization procedure. A particular electromagnetic circuit is adapted to experimentally achieve the demagnetization characteristic to estimate the air gap magnetic flux behaviour in electrical machines. The measurement system flexibility allowed the testing of two double-layer magnets: the so-called parallel and series arrangements.