An improved predictive current control for IM drives

Abstract

In Finite Control Set-Model Predictive Control (FCS-MPC), the model of the induction machine (IM) is expressed in the a b or d q reference frame, and then the back-EMF is estimated based on the applied voltage vectors. In this work, the d-q reference frame is used but unlike the existing method, the esti- mated back-EMF is calculated by filtering the voltage vectors. Moreover, the work studies the importance of the discretization method on the predictive control behavior of IM. It has been demonstrated that the mentioned enhancements lead to an efficient Total Harmonic Distortion value for stator current (THD i) and torque ripple reduction compared to the conventional methods. The proposed Predictive Current Controller (PCC) has been validated experimentally by using a commercial IM of 7:5½kW controlled by a dSpace 1103 real-time control board running with sample frequencies from 10½kHz to 80½kHz . The test results validate the developed controller’s ability to meet the control objectives in a whole range of speeds, loads, and sampling frequencies.