### Title: Simulation and analysis of heat losses of in-wheel motor for micro-electric vehicles

Authors: Qiping Chen; Qiang Xiao; Sheng Kang; Liping Zeng; Chuanjie Liao; Xiangqin Li

Addresses: Key Laboratory of Conveyance and Equipment Ministry of Education, East China Jiaotong University, Nanchang 330013, China ' Key Laboratory of Conveyance and Equipment Ministry of Education, East China Jiaotong University, Nanchang 330013, China ' Key Laboratory of Conveyance and Equipment Ministry of Education, East China Jiaotong University, Nanchang 330013, China ' Key Laboratory of Conveyance and Equipment Ministry of Education, East China Jiaotong University, Nanchang 330013, China ' Key Laboratory of Conveyance and Equipment Ministry of Education, East China Jiaotong University, Nanchang 330013, China ' Key Laboratory of Conveyance and Equipment Ministry of Education, East China Jiaotong University, Nanchang 330013, China

Abstract: Heat losses of in-wheel motor for micro-electric vehicles are computed and analysed, which can enhance the dependability, efficiency, safety and lifetime for in-wheel motor. The theory-practice combination method is adopted. The computational mathematics model of heat losses is set up, which is regarded as the study goal. The field-circuit coupling and the electromagnetic-thermal coupling model are regarded as the breakthrough point, and electromagnetic structures of in-wheel motor are systematically optimised. The control equations of incremental steps alternating solving multiple fields are calculated and analysed. An electromagnetic-thermal coupling calculation model is established. Calculation results are verified to illustrate heat losses principle and uncover the internal mechanism of electromagnetic-thermal coupling field for in-wheel motor. This paper will propose a complete set of integrated modelling method and coupling algorithm of electromagnetic-thermal coupling field, which can provide theoretical and technical support for improving in-wheel motor quality and property of micro-electric vehicles.

Keywords: analysis; heat losses; simulation; coupled solution; in-wheel motor of micro-electric vehicles.

International Journal of Electric and Hybrid Vehicles, 2018 Vol.10 No.1, pp.70 - 81