Modeling of cross-magnetization effect in interior permanent magnet machines

Electric parameters of interior permanent magnet (PM) synchronous machines have a non linear characteristic due to saturation effects. Thus, d-q axes inductances are not constant, but they vary depending on the load conditions and the current phase angle. Generally, this kind of machine is characterized by a cross-magnetization effect between axes so that an ideal uncoupled d-q model is not suitable to represent the performance of the motor. In this work a steady state coupled d-q model which takes into account these non linearities is presented. An interior PM synchronous machine is analyzed in finite elements (FE) and the flux linkages as function of current amplitude and load angle are obtained. Then, analyzing these results a non-linear d-q model is proposed.