Experiment and Simulation Study on the Cooling Performance of Oil-Cooling PMSM with Hairpin Winding

In this paper, the cooling performance of oil-cooling PMSM with hairpin winding under various oil parameters is analyzed via a simulation and an experiment. The effects of oil jet positions, oil temperatures, and oil flow rates on the cooling performance are analyzed. It is found that increasing the oil temperature in the range of 20 degrees C to 60 degrees C, increasing the flow rate of oil jets whose position angle is from 15 degrees to 45 degrees, and increasing the flow rate in the range of 1 L/min to 2 L/min will significantly improve the cooling performance. The apertures of the oil spray ring are optimized using the Taguchi algorithm. The cooling performance is the best when the flow ratio is m(0 degrees):m(15 degrees):m(30 degrees):m(45 degrees):m(60 degrees):m(75 degrees) = 4%:19%:10%:10%:4%:4%. This study provides a guide for the design of the oil-cooling system for the hairpin winding of the PMSM.