A review of in-wheel motors for electric vehicle propulsion

The concept of hub motors or in-wheel motors (IWMs) in electric vehicles (EVs) as a replacement for conventional internal combustion engines has received significant attention in recent years. Since integrating the motor into the wheel eliminates the transmission system and significantly increases the efficiency, IWMs are considered as efficient and innovative solutions for the drive systems of future EVs. Therefore, it is useful to present a comprehensive review of the recent developments of the IWMs and discuss their potential future advancements. In this paper, the major topologies of IWMs are systematically reviewed, such as permanent magnet IWMs (PM-IWMs), magnetic-geared IWMs (MG-IWMs), in-wheel switched reluctance motors (IW-SRMs), and wireless IWMs (W-IWMs). The advantages and drawbacks of these IWM topologies are investigated and compared. Finally, the challenges and future trends of the IWMs are discussed in detail.