Multi-task control strategy for grid-tied inverters based on conservative power theory

• Published in: IET renewable power generation 2015-03, Vol.9 (2), p.154-165
• Main Authors: Marafão, Fernando Pinhabel, Brandão, Danilo Iglesias, Costabeber, Alessandro, Paredes, Helmo Kelis Morales
• Format: Article
• Language: English
• Subjects: Active control; active power absorbtion; active power filter; active power injection; conservative power theory decomposition; Control systems; current waveform; decentralised control; DG control system; distributed generation inverter; distributed generator; distributed power generation; Electric potential; Inverters; invertors; load current disturbance mitigation; Markets; multitask control strategy; photovoltaic; power filters; Power generation; power generation control; power generation decentralizing; power generation economics; power grid tied inverter; power grids; power markets; power quality improvement; power supply quality; renewable energy source market; renewable energy sources; small hydro; Strategy; switching power interface; voltage drop compensator; waveform analysis; Waveforms; wind
• ISSN: 1752-1416; 1752-1424; 1752-1424
• DOI: 10.1049/iet-rpg.2014.0065

ln recent years, the concept of decentralising power generation through the deployment of distributed generators (DGs) has been widely accepted and applied, driven by the growing market of renewable energy sources. These DGs are normally equipped with a switching power interface, acting as front end with the grid. This paper proposes a multi-task control strategy for distributed generation systems that simultaneously allows the DG to inject the available energy, as well as to work as a voltage drop compensator or as an active power filter, mitigating load current disturbances and improving power quality of the grid. The main contribution of the proposed system, with respect to other solutions in the literature, is that the proposed control loops are based on the Conservative Power Theory decompositions. This choice provides decoupled power and current references for the inverter control, offering a very flexible, selective and powerful control strategy for the DG. The paper also discusses the choice of the current waveform for injecting/absorbing active power into/from the grid, and both sinusoidal and resistive references have been compared in terms of damping capability. Finally, simulation and experimental results are provided in order to validate the proposed functionalities of the DG control system.