Predictive Control Strategy for DC/AC Converters Based on Direct Power Control

Abstract

This paper proposes predictive direct power control (P-DPC), a new control approach where the well-known direct power control is combined with predictive selection of a voltage-vectors' sequence, obtaining both high transient dynamics and a constant-switching frequency. The developed P-DPC version is based on an optimal application of three voltage vectors in a symmetrical way, which is the so-called symmetrical 3 + 3 vectors' sequence. The simulation and experimental results of the P-DPC are compared to standard voltage-oriented control (VOC) strategies in a grid-connected three-phase voltage-source inverter under 400-V 15-kVA operation conditions. The P-DPC improves the transient response and keeps the steady-state harmonic spectrum at the same level as the VOC strategies. Due to its high transient capability and its constant-switching behavior, the P-DPC could become an interesting alternative to standard VOC techniques for grid-connected converters