Grid-Tie inverter for photovoltaic distributed generation with injection control of active and reactive powers and capability of Islanded operation mode

Abstract

This research proposes the development of methods for the control and protection of the three-phase inverter structures, up to 30kVA, applied to Distributed Generation Photovoltaic Systems with accumulation capacity, considering the connected mode (Grid -Tie Mode) at the AC public electric power distribution network in low voltage, with the possibility of operating in islanded mode and capability of Active and Reactive power injections.In this context, considering energy efficiency and agreement to the power quality standards for "Solar Inverters" in Distributed Generation (DG), connected to AC distribution networks, considering the possibility of island mode operation, this research aims to design and analyze the performance of a three-phase inverter for photovoltaic DG with injection capacity of active and reactive powers into the grid, considering a system with accumulation in lithium-ion batteries, allowing grid-tie and islanded operations.Therefore, considering the previous researches developed at LEP-Power Electronics Laboratories/UNESP, this research has the main goal of contributing to the state of the art for the development of structures for photovoltaic inverter applications that have the capabilities as ancillary regulation services (injection of active and reactive powers) in grid-tie operation, as well as to operate in islanded mode, feeding priority loads with regulation capacity (Voltage (V) and Frequency (f)) of these micro-grids, with the purpose of the management and integrated control of the DG resources, considering energy efficiency and assurance for the energy Power Quality (PQ) indices (power flow control, energy efficiency, losses reduction, improvements for the general indicators of PQ, and allowing safe operation (considering IEC, IEEE, NBR standards) in its different modes of operation (grid-tie or islanded). (AU)