Temperature rise in induction motors under stall conditions

A combined electrical and thermal model has been described which allows the accurate calculation of locked-rotor temperature rise from a knowledge of the simple equivalent circuit parameters and the physical dimensions of an induction motor. The model includes the effects of spatial bar current variations, nonuniform loss distribution and three-dimensional heat flow. Its use allows the design engineer to assess the effects of stall conditions upon the integrity of the cage structure and aids in correct specification of stall protection equipment to ensure safe and reliable motor operation.<>