Study and analysis of a natural reference frame current controller for a multi-level H-bridge power converter

In order to pave the way to a sustainable energy future based on a large share of distributed generation (DG), there is a clear need to prepare the European electricity system for the large-scale integration of both renewable and other distributed energy sources. Advanced power electronic converters for DG will be needed in order to control the power flow and to ensure proper and secure operation of this future grid with an increased level of the renewable power. These power converters must be able to provide intelligent power management as well as ancillary services. This paper presents an analysis of the natural reference frame controller, based on proportional-resonant (PR) technique, for a multi-level H-bridge power converter for universal and flexible power management in future electricity network. The proposed method is tested in terms of harmonic content in the point of common coupling (PCC), voltage amplitude and frequency excursions as well as system response for bidirectional power flow. The presented results confirm the effectiveness of the proposed control strategy.