Construction of a Calorimetric Test-rig for Loss Measurements on Induction Machines

This thesis presents the development and construction of a cooling system and a calorimetric set-up for efficiency measurements on an 11 kW induction machine. Direct and indirect methods of efficiency determination and loss segregation is presented. An analytical thermal model of the machine is used for the estimation of different motor temperatures. The results are verified by measurements. The methodology for calibration of the specific set-up is presented and performed. An accuracy of ・} 5 mK for the calorimetric temperature measurements is obtained. Measurements have been performed in order to determine the thermal leakage of the test-setup. It was found that the main leakage path is through the rotor shaft. According the the measurements performed, this leakage is lower than 1.6 % of the active input power