Detecção de ilhamento a partir da injeção de pequenos sinais através do inversor presente no gerador distribuído

Abstract

The deployment of distributed generators based on renewable sources is considered an alternative to suplly the growing demand for electric energy, improving the energy e ciency done in the system and at the same time reducing environmental impacts. However, when the main generating unit is disconnected, a portion of the system remains energized due to the presence of these secondary electric power units, thus forming an island in a part of the Electric Power System, a situation that is not desired because it can cause problems related to power quality and safety system operation. Thus, this work presents two techniques of islanding detection from the injection of small signals through the present inverter of the DG, in which the rst techniques identi es the islanding from the impedance variation, while the second is based on the rate of change of frequency of the system caused by these disturbances. The results were obtained through simulations of the PSIM software, where, through these two methods, it is possible to detect the occurrence of the islanding in less than 400 ms without these small injected signals take the system out of its operating margins established by the regulatory agencies.