Model Calibration of Oil Jet and Oil Spray Cooling in Electrical Machines with Hairpin Windings

In recent years, the automotive industry has seen increasing applications of oil cooling in drivetrain designs. Oil jet cooling is one of the most popular schemes that can be found in many modern commercial products. However, literatures focusing on the topic are few. This paper presents a new way of modelling electrical machines with hairpin windings and oil jet cooling using experimental data. A custom build experiment setup is used to conduct oil jet cooling experiments on a stator with hairpin windings. The modelling of the machine is performed with Motor-CAD software using a new type of thermal resistance network. The proposed workflow is also applied to spray cooling designs. Simulation results and experimental results show good agreement with each other, suggesting that the proposed workflow can be used to facilitate designing of similar electrical machines.