Five-Phase Induction Motor Rotor Current Observer for Finite Control Set Model Predictive Control of Stator Current

Model predictive control (MPC) has recently been applied to induction motor (IM) drives in a configuration known as finite control set MPC (FCS-MPC). Its implementation must solve the problem of estimating rotor quantities, a task that is usually done using a simple backtracking procedure. On the other hand, observers have been used with field-oriented control (FOC), sensorless drives, and for fault detection but they have not been used yet for finite control set predictive current control of drives. This paper shows the benefits of incorporating a rotor current observer in a finite control set model predictive controller for the stator current of a five-phase drive. The observer design methodology employed in this work uses pole placement based on Butterworth filter design. The new estimation scheme is compared with the standard one in which nonmeasurable state components and other variables are lumped into one term that is updated. The differences between both approaches are experimentally analyzed and verified.