Simulation of inverter fed induction motors including core losses

The authors consider the development of a simulation model for an induction motor including both eddy current losses and hysteresis losses. Since both eddy current loss and hysteresis loss are frequency-dependent, a novel induction motor model with stator and rotor circuits expressed in different reference frames is presented to facilitate analysis. As the eddy current and hysteresis losses are ohmic, the stator and rotor eddy current losses can be represented by resistors across the stator and rotor magnetizing inductances. Necessary equations are derived to calculate the values of these resistors. Using the developed model and simulation equations, a simulation of a 250 HP squirrel cage induction motor was implemented. The proposed model is particularly suitable as a building block to generate a suitable PWM (pulse-width modulation) pattern that has minimum motor losses