End Space Heat Transfer Coefficient Determination for Different Induction Motor Enclosure Types

In this paper the determination of the end space induction motor heat transfer coefficients is presented and the methodologies used are examined closely. Two "ad hoc" prototypes have been built and a test bench completed. This paper reports the set up of the test procedures and results obtained in detail. As the end-windings are the hottest points of the motor particular care has been devoted to the determination of the heat transfer coefficient concerning the end-winding structure. The results obtained are of fundamental importance for the determination of the thermal resistances between end-windings and end caps. These can then be used in thermal networks usually adopted in thermal model analysis.