Design and analysis of different cooling schemes of a flux‐modulated permanent magnet in‐wheel motor for electric vehicle applications

Abstract

The flux-modulated permanent magnet (FMPM) in-wheel motor has provided a promising solution to drive electric vehicles (EVs) because of its salient features such as tight structure, high power (torque) density, and high transmission efficiency. But it easily causes excessive temperature rise and limits the torque output due to the poor heat dissipation capacity inside the in-wheel cavity. In this regard, a 3D fluidic-thermal coupled model integrating computational fluid dynamics and numerical heat transfer is proposed and validated by experimental results on a 2.1 kW, 1800 rpm PM motor prototype. The temperature rise distribution of a 22.6 kW, 600 rpm FMPM in-wheel motor under an existing natural cooling structure is then numerically investigated. It is revealed that it is difficult to satisfy the thermal requirements of the motor using only natural cooling approach. Consequently, a self-ventilated cooling system and a non-contact lead-in (NCLI) system are used to maintain the temperature rise. In addition, to further improve the heat dissipation capacity, the NCLI structure is modified with water cooling channels separated by orifice plates to limit the excessive motor temperature rise. The motor temperature rises under different cooling schemes are analyzed to verify the effectiveness of the proposed cooling structures. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Investigation of a Low-Speed High-Torque-Density Direct-Drive External-Rotor PMSM for Belt Conveyor Application

“…At present, water cooling is the most direct and effective way to reduce the motor temperature [23][24]. Due to the external rotor structure of the proposed LHDERPMSM, the inlet and outlet of cooling water cannot be directly installed on the shell like the outer stator PMSM.…”

Overview of the Potential of Energy Harvesting Sources in Electric Vehicles

“…Battery temperatures below 40 • C have been reported in references [34][35][36][37][38][39][40][41]. Meanwhile, studies such as [42][43][44][45][46][47][48][49] measured temperatures ranging from 40 • C to 60 • C, with [50,51] recording temperatures higher than 60 • C. Temperature changes in electric motors can be classified into three groups: less than 50 • C, as seen in [52], between 50 • C and 100 • C, as seen in [53][54][55][56][57][58][59] and above 100 • C, as seen in [60][61][62][63][64][65].…”

Comprehensive Review on Cooling of Permanent Magnet Synchronous Motors and Their Qualitative Assessment for Aerospace Applications

“…However, these can also change the magnetic flux path due to additional reluctance. The addition of an orifice plate in the stator cooling channel, which effectively redistributes the water in the stator and end windings, was tested on a 22.6 kW motor [17]. When compared to the standard air ventilation cooling, the improved design showed a temperature drop of 81.5 • C in the winding.…”