Analysis of End-Winding Heat Transfer in a Low-Speed Motor With Forced External Cooling

This article describes end-winding heat transfer under forced external cooling, a cooling arrangement which is not commonly studied in literature. The average end-winding heat transfer under different rotational speeds and external coolant supply is studied through the use of computational fluid dynamics. As a result of the analysis, an analytical expression for the combined effect of rotation and external forced cooling is proposed. Finally, the established expression is used in an lumped-parameter thermal-network analysis and resulting temperatures are compared with corresponding measurements.