现有的对电动汽车驱动电机水冷系统的研究主要集中在水冷系统的换热能力方面，对压力损失考虑不够． 针对这一问题，文中首先以常用的驱动电机——永磁同步电机为对象，通过理论计算分析了流道结构参数对换热能力和压力损失的影响，发现流道螺旋圈数对换热和压力损失均有较大影响，而流道截面尺寸的变化对换热能力几乎没有影响，对压力损失影响较大，发现流道螺旋圈数对换热和压力损失均有较大影响，而流道截面尺寸的变化对换热能力几乎没有影响，对压力损失影响较大，提出了考虑换热能力和压力损失的流道设计方法，为高功率密度永磁同步电机水冷系统的设计提供了参考．

As the existing researches on the water cooling system of motors applied to electric vehicles mainly focus on the heat exchange performance without taking full consideration into pressure loss,the influences of cooling channel parameters on heat exchange performance and pressure loss are analyzed theoretically for the frequently- used driving motor-permanent magnetic synchronous motor ( PMSM),finding that the twist number of cooling chan- nels influences heat exchange and pressure loss greatly,and that the transverse dimensions of cooling channel have little influence on heat transfer but have great influence on pressure loss.Thus,an optimal range of cooling channel parameters is obtained,with its validity being verified by simulating PMSM temperature field and pressure loss of cooling channels with optimized parameters through a finite element analysis.Finally,a new design method of cool- ing channels considering both heat exchange and pressure loss is presented.The research provides a reference for the design of water cooling system of PMSM with high power density.