A generalized Epstein test method for the computation of core losses in induction motors

Modeling and definition of procedures leading to good estimation of core losses in induction motors from material test data is still a challenge. Complex geometry of the laminations, concentration of current in discrete number of slots and PWM inverter supply further increase the complexity of induction motor core losses model. In this paper, it is proposed an alternative for the modeling and computation of the stator core losses in induction motors based on lab tests of samples of the magnetic material with simple geometry. The proposed method accounts for effects such as flux space harmonics, PWM inverter supply, material anisotropy and cutting stress during the manufacturing process. Models, test methods and practical results from a 2 hp, 220 V, 4 pole, high efficiency three-phase induction motor, employing E-170 steel, are presented and discussed in detail.