Speed adaptive flux Luenberger observer used in sensorless vector control of an unbalanced six-phase induction machine

In this paper, a speed adaptive flux Luenberger observer is presented for sensorless control of a squirrel cage six phase induction machine (SC6PIM) in healthy and faulty condition. Model of an induction machine in unbalanced operating situation is presented and used to estimate the states of SC6PIM in fault condition by using Luenberger observer and an adaptive speed system. Rotor flux and speed obtained from the observer in unbalanced condition is used in vector control. To ensure the capacity of the observer performance in unbalanced conditions, one, two and three of six phases are lost in experimental test respectively. Also in all tests, maximum value of inertia variation is considered in experimental test as mechanical disturbance.