Direct Torque Control with variable duty-cycle in induction motor drives using 3-level inverters

Abstract

The paper deals with Direct Torque Control of high-power induction motor drives using a 3-level inverter. In order to overcome the problem of flux magnitude and torque oscillations, an optimized algorithm is proposed. The sampling time is subdivided in some elementary parts, where different voltage vectors are applied. These are evaluated by means of a simplified mathematical model in order to keep flux and torque within assigned hysteresis bands.