Effects of Recycled Permanent Magnets on Electric Machine and Hybrid Electric Vehicle Performances

Abstract

Permanent magnet price volatility is an ongoing issue that affects many industrial sectors worldwide, dictating the costs of the final product by a substantial degree. This fluctuation can be attributed to a large concentration of NdFeB magnet production and material sourcing occurring in concentrated geopolitical areas, thus motivating institutions and governments to look elsewhere for magnet material for various applications. The work presented in this paper aims to determine the viability of recycled permanent magnets in electric machines used within the automotive industry. Magnet recycling incentives are presented, along with the two main routes for magnet reprocessing. They are briefly compared to present the route selected within this study. The recycled magnets used in this study are characterised such that relevant parameters are extracted for further analyses. A P2 hybrid electric vehicle is modelled and its energy management system presented, being an Equivalent Consumption Minimisation Strategy. The performance evaluation of a baseline machine at component level is performed, with its affect on vehicle performance quantified, followed by the recycled magnet machine’s characterisation and subsequent performance evaluation at vehicle level. The recycled magnets inhibit a minor efficiency degradation at component level, leading to a performance degradation of about 0.11% at vehicle level.