Thermal and mechanical optimization of water jacket of permanent magnet synchronous machines for EV application

Water jacket of permanent magnet synchronous machines (PMSMs) not only undertakes the responsibility of heat dissipation, but also mechanical protection. However, due to PM drive motors of electric vehicles (EVs) working under the states of starting, accelerating and climbing in a harsh environment usually, which make the water jacket damage easily. This paper main investigate the optimization design of water jacket of the PMSM for ensuring the EV works steady. Firstly, an optimization scheme of water jacket is given in this paper, in which a convection heat transfer factor is proposed for evaluating the optimal number and size of water channel in the water jacket. Secondly, mechanical stress analysis is implemented on the water jacket for obtaining the optimal thickness of inner layer of water jacket. Finally, thermal analysis demonstrates the PMSM with the optimal water jacket has a good cooling capability. Some references about the cooling system design can be given in this paper.