Field-oriented Control of an Induction Machine with Winding Asymmetries

Modern electrical AC drives with best available performances are based on the so-called fundamental wave machine model approaches. This paper introduces an upgrade of fundamental wave model approach by respecting both inherent and fault-induced deviations of machine flux from its fundamental component. A field-oriented control scheme for an asymmetric induction machine is presented. The algorithm is based on observing newly introduced flux-angle-based variations in the transient leakage inductance due to the asymmetry. A simple extension of the conventional rotor field-oriented control structure is proposed that takes into account detected variations and improves machine performance in the asymmetry conditions. Detection and characterization of newly formed modulation in transient leakage inductance are performed by employing an unscented Kalman filter. Simulation results for the case of a 5.5 kW induction machine are presented.