Novel Liquid Cooling Technology for Modular Consequent-Pole PM Machines

In this paper, a forced oil cooling scheme is proposed for a novel modular consequent-pole permanent magnet machine (CPM) with E-core stator. In this modular machine, flux gaps (FGs) that are normally used for improving electromagnetic performance and simplifying the winding process, can also be utilized as cooling channels for the oil to pass through, leading to significantly improved machine internal cooling. Computational fluid dynamics (CFD) analyses have been carried out and the results indicate that circa 15°C reduction in the peak temperature can be achieved based on the initial design. Moreover, the influences of several other critical parameters such as inlet position and geometry have been investigated, and optimal inlet configurations have been identified to realize the temperature uniformity. Some useful design guidelines for thermal management in the modular CPMs have also been provided in this paper.