Modeling for control of non-sinewave permanent-magnet synchronous drives by extending Park's transformation

An extension of Park's transformation is proposed for non-sinewave permanent-magnet synchronous machines with constant airgap. For sinewave machines, Park's classical transformation allows working within the rotor's reference, so that the vector of the rotor fluxes variations would have just one component Φ′rq. For the non-sinewave machines, a new reference frame is proposed, which permits to obtain a simple torque expression, through setting at zero one of the components of the vector of the rotor fluxes variations. By means of this modeling, optimal steady state currents have been computed for this kind of drive. Extended Park model has been validated through a finite element code. This analytic model is here used to analyse the steady state (comparison with 120° voltage control is conducted), but is destined to determine dynamic control laws, particularly vector control.