Predictive Direct Power Control of MV Grid-connected Three-level NPC Converters

This paper deals with an improvement of the predictive direct power control (P-DPC) for MV three-level NPC converters. Contrary to the previously developed P-DPC strategy, the proposed approach combines a symmetrical 3+3 voltage vectors´ sequence for the steady-sate operation with a simple two voltage vectors´ sequence for transient requirements. Simulations of the proposed hybrid algorithm are compared to a standard voltage oriented control (VOC) under 2.3 kV-2 MVA operation conditions. Both the P-DPC and the VOC strategies offer similar steady-state performances but the P-DPC is clearly better during transients. These results match with the expected behavior and reinforce the choice of P-DPC as an attractive candidate for the control of MV grid connected converters.