A novel satisfactory model predictive control based on current variance for high power three-level-NPC rectifiers

Abstract

Here, a novel satisfactory model predictive control based on current variance (CV-SMPC) is proposed for three level neutral point clamped (NPC) rectifiers. CV-SMPC achieves global optimization of multiple control objectives rather than optimal control of a single control objective with the satisfaction interval. The current satisfaction interval is adjusted online based on the current variance in the CV-SMPC. The relationship between the current total harmonic distortion (THD), switching frequency, and current variance is established through experimental investigation, enhancing the comprehensibility of control effects. In addition, three simplified sets of candidate vectors are proposed based on the voltage satisfaction interval, thereby reducing the computational burden. Furthermore, the control objectives are categorized into three levels and sequentially combined, eliminating the laborious process of adjusting the weighting factors. Finally, the experimental results conclusively demonstrate the exceptional control performance of CV-SMPC in both steady-state and dynamic processes.