Predictive torque control of induction machines fed by 3L-NPC converters with online weighting factor adjustment using Fuzzy Logic

Direct model predictive control (DMPC) is a simple and powerful method for power converters, thanks to its fast control dynamics and the capability to deal with multiple constraints. Weighting factors are typically the only adjustable parameters in the cost function but will affect the performance of system dramatically. The selection of the weighting factors is usually tedious and can be considered as an open question. In this paper, a simple but effective method is proposed to deal with the weighting factor design of direct predictive torque control for induction machine drives fed by three-level neutral-point clamped power converters. To achieve a systematic design and online tunable weighting factors at reduced controller design efforts, a Fuzzy Logic based solution is utilized. The effectiveness of the proposed method is validated by experimental data at lab-constructed test-bench with FPGA based digital controller.