Predictive Torque Control of Five-Phase Induction Motor Drive Using Successive Cost Functions for CMV Elimination

Abstract

This article presents a predictive torque control (PTC) algorithm for a five-phase (distributed winding) induction motor fed by a three-level neutral-point-clamped inverter to remove the common-mode voltage (CMV). In this approach, a finite range of 31 voltage vectors (VVs) is chosen from the total available 243 VVs for the removal of the CMV. The xy-subspace current harmonic reduction is achieved with grouped VVs. The developed PTC algorithm has two successive cost functions: g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1h</sub> for stator flux and electromagnetic torque regulation and g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2h</sub> for xy-subspace current harmonic reduction. The purpose of these two successive cost functions is to reduce the complexity in determining the independent weighting factors. This algorithm retains the torque and flux responses similar to that of conventional PTC. The minimization in switching frequency is obtained in the presented PTC algorithm with the selected set of VVs. For evaluating and ascertaining the capabilities for CMV elimination and xy-subspace harmonic current reduction, the proposed algorithm is compared with the conventional PTC algorithm having a different set of VVs. Experimental outcomes show the significance of the discussed algorithm in the steady state and retain the transient operating conditions.