Nonexcessive-ΔV and Low Complexity Model Predictive Control Based on Finite-State Machine for Three-Level Three-Phase Inverters

Abstract

For three-level three-phase inverters, a novel finite-state machine based model predictive control (FSM-MPC) is proposed. The state transition diagram of FSM is regarded as the operation guideline to avoid excessive voltage jumps (Δ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> ). No more than five voltage vectors (VVs) are selected as FSM-MPC's candidates VVs, based on the VV reference and the previous optimal VV. And the cost function is simplified in terms of time duration. Thus, evaluating a candidate VV requires a very low computation cost. Without losing control performance, the proposed FSM-MPC's execution time is decreased to 50% of the MPC algorithm, which enumerates all basic VVs to get global optimal VV and performance. Compared to the existing simplified algorithms, the proposed FSM-MPC makes current harmonics lower, and its average switching frequency is 33% less, which means much less switching loss. Furthermore, the proposed algorithm is robust when the electric-circuit parameters are mismatched in the control system. Experimental results are provided to validate the advantages of the proposed algorithm. <fn fn-type="other" id="fn3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This work was supported in part by National Natural Science Foundation of China under Grant 52177204, and in part by Natural Science Foundation of Hunan Province under Grant 2021JJ30875. (Corresponding author: Jian Yang) H. Zhou, J. Yang, D. Song and M. Dong are with the school of Automation, Central South University, Hunan 410083, People's Re-public of China (e-mail: ; ; ; ). L. Huang and X. Chen are in Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China (e-mail: ; ). </fn>