Dual three-phase machine modeling and control including saturation, rotor position dependency and reduction of low current harmonics

This study presents investigations on modeling and control of dual three-phase internal permanent magnet machines with distributed thirty degree electrically shifted winding sets. An approach how to model the additional dependencies accompanied with dual three-phase machines is presented. Especially rotor position and saturation of the inductances have to be taken into account in order to enable the modeling of current harmonics. Also, due to manufacturing reasons, asymmetries and unbalances between the two three-phase subsystems are possible. This leads to large amplitude differences in the phase current which further results in a limited operational range. The proposed modeling approach enables control development to minimize above mentioned parasitic effects, adopting existing decoupled d-q-proportional integral control based on vector space decomposition methods. The transfer of these current harmonics compensating control strategies to an electric vehicle operating range is demonstrated while considering possible unbalances between the two separate three-phase systems. Furthermore, test bench operation is performed to verify the modeling approach and the control performance.