New vector controller for PM motors which modeled the cross-coupling magnetic flux saturation

A new magnetic-flux saturation model has been developed for permanent magnet synchronous motors. In the new model, simple first-order functions Φ_d(i_d, i_q) and Φ_q(i_d, i_q) express the relationships between d-q axis currents and each axis magnetic flux, considering magnetic saturation and cross-coupling effects. Taking advantage of these new features, we developed a current controller that introduced the precise inverse model of the motor using the above function. Furthermore, simulations of the proposed current controller were evaluated under ideal conditions without any modeling error. Moreover, it showed, in principle, that the ideal first-order lag characteristic without the current interference between d-q axes could be realized in the conditions of cross-coupling magnetic flux saturation.