A detailed induction machine core loss model in the arbitrary reference frame

Although reference frame theory is fundamental for machine modeling and control, core loss is commonly ignored in the quadratic-direct-zero (qd0) frame machine models. This paper proposes and validates a new analytical core loss model of an induction machine in the arbitrary qd0-frame. The proposed model is based on the machine´s dynamic model in the three-phase abc-frame with a core loss branch integrated in each stator phase. The qd0-frame equivalent circuits are obtained using the reference frame transform and are used to derive analytical expressions of copper loss and core loss. Detailed analysis and mathematical derivation of the model are given as well as simulation implementation and verification in MATLAB/SIMULINK. The proposed core loss model is then compared to experimental measurements using 1.5HP, 3HP and 10HP machines in line-fed scenarios. Results show less than 1% estimation error between the proposed model and experiments.