Study on rare-earth-free electric machine for EV/HEV

• Main Author: Liu, Chengming
• Other Authors: Christopher H. T. Lee
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Motor drive; Non-rare earth
• Online Access: https://hdl.handle.net/10356/176578
• Institution: Nanyang Technological University

Electrical machines are widely used these days. There are varying types of machines, which provide disparate features for various applications. Permanent Magnet Machines (PMMs) are commonly utilized for Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) nowadays. Based on the location of the permanent magnets, the topologies of PMMs can be further classified. The rare-earth permanent magnets are the permanent magnet materials usually utilized in electrical machines. The most widely used rare-earth permanent magnet material for electrical machines is Neodymium Iron Boron (NdFeB) magnets. However, rare-earth materials also take the disadvantages of expensive, unstable supply, and environmental concerns. The two main solutions to reduce the usage of rare-earth materials are using non-rare-earth magnets or windings to replace the rare-earth magnets. Many research and simulations have been conducted and several rare earth-free machines are implemented in literature. This paper aims to look into certain issues like the lower torque density and power factor that existing rare earth-free machines have. Other structures of machines, for example, rare earth-free vernier machines, will be further investigated. The comparison with the rare earth-based machines will be carried out in this paper as well.