Experimental Study Of Oil Cooling of Large Electric Machine For High Power Application

As power density in electric machines continues to rise, particularly in the static components housing copper, the development of efficient and reliable cooling strategies becomes imperative. This paper focuses on the experimental investigation of oil-jet cooling applied to a segment of winding representing the end-windings of a high-power electric machine’s stator. The coils subjected to the oil jet are meticulously instrumented, enabling comprehe nsive monitoring of temperature distribution across the entire coil surface. Our study showcases the effective ness of this cooling technique, revealing a maximum temperature of $84^{\circ} \mathrm{C}$ on the end-windings under oil jet. Additionally, we conduct evaluations using various oils characterized by different viscosity ranges and thermal conductivities. Our findings culminate in a comparative analys is of oil-jet cooling against alte rnative methods, including air jet cooling and parallel air flow.