Eddy-Current Loss Modeling for a Form-Wound Induction Motor Using Circuit Model

Eddy-current losses in a form-wound stator winding of a 1250-kW cage induction motor was modeled using time-discretized finite- element analysis (FEA). A simpler and faster model, typically a circuit model, is needed to include these losses in the loss control algorithms of a frequency converter. The conventional T-equivalent circuit was augmented by an additional branch both in the stator and rotor to model the eddy-current effects. The parameters of the refined circuit were estimated using the voltages and currents from the FEA simulations. The circuit model was verified by comparing the calculated losses and torque with those obtained from the FEA.