Extended Period Control Approach FCS-MPC for Three Phase NPC Power Converters

• Published in: IEEE transactions on power electronics 2024-12, p.1-11
• Main Authors: Aguirre, Matias, Vazquez, Sergio, Wilson-Veas, Alan H., Kouro, Samir, Rojas, Christian A., Leon, Jose I., Franquelo, Leopoldo G.
• Format: Article
• Language: English
• Subjects: Finite control set; fixed switching frequency; model predictive control; three-level neutral point clamped voltage source converter
• ISSN: 0885-8993
• DOI: 10.1109/TPEL.2024.3511263

Finite control set model predictive control (FCS-MPC) selects a voltage vector state at fixed sampling period without the use of a modulator. As a direct consequence, the conventional implementation of FCS-MPC presents variable switching frequency. Period control approach (PCA-FCS-MPC) for a two-level three-phase inverter is effective in controlling the switching frequency without the need of a modulation stage. However, its implementation for a three-level three-phase inverter is not straightforward due to the need for synchronizing the commutation of all the power semiconductors in each leg. This work presents a new method to implement this strategy in a three phase Three-Level Neutral Point Clamped Voltage Source Inverter (NPC-VSI), named direct grouping, which modifies the approach of PCA such that its implementation becomes possible on the NPC-VSI. This new method, along with a state-of-the art solution, are analyzed in detail to establish a metric for the evaluation of their performance, from which the new proposal shows improved outcome. Experimental results validate the switching frequency control performance, flexibility and efficacy of the proposed strategy.