Many electric traction drive systems (ETDSs) are driven by electric motors primarily composed of high-energy rare-earth (RE) permanent magnets (PMs), such as neodymium–iron–boron (NdFeB) and samarium–cobalt (SmCo). Given the high cost of RE materials, there is a great interest among various industry sectors in searching for breakthrough technologies that reduce the consumption of high-energy RE magnets in their electromechanical energy conversion systems. The reduction of the magnetic volume is typically realized either by replacing a portion of the high-energy RE magnet with the low-energy ferrite magnet (knows as hybrid structure) or by modifying the magnetic arrangement of the machine itself, where a portion of the physical RE magnets is removed and replaced by induced magnets (known as consequent-magnetic pole structure). For this purpose, this article presents a review of the current state-of-the-art motor typologies with less-RE PMs and their key design challenges, followed up by a series of recommended guidelines to overcome related design challenges.

中文翻译：

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减少电机中稀土永磁体的使用：综述

许多电力牵引驱动系统 (ETDS) 由主要由高能稀土 (RE) 永磁体 (PM) 组成的电动机驱动，例如钕-铁-硼 (NdFeB) 和钐-钴 (SmCo)。鉴于 RE 材料的高成本，各行业部门对寻找突破性技术以减少其机电能量转换系统中高能 RE 磁体的消耗非常感兴趣。磁性体积的减小通常是通过用低能铁氧体磁体（称为混合结构）替换一部分高能 RE 磁体或通过修改机器本身的磁性排列来实现的，其中一部分物理 RE 磁体被移除并替换为感应磁体（称为后续磁极结构）。以此目的，