Electrical-thermal modeling of a double-canned induction motor for electrical performance analysis and motor lifetime determination

In nuclear and chemical fields, canned motor pumps are one of the safest ways to pump dangerous fluids. The canned motor pump is a compact unit integrating a hydraulic part and an induction motor with a common shaft. The particularity of the motor is that two non-magnetic cans are inserted in the air gap for leak tightness reasons. This study is therefore motivated by the fact that on one side classical electromagnetic and thermal models are not applicable for the canned motor, and on the other side new European standards about electrical machines require the design of motors with higher efficiency. In this work, an analytical model that combines electrical and thermal approaches has been performed to determine both electrical performances of the canned motor and the stator lifetime through the prediction of the maximum temperature of the winding for different operating conditions.