Geração distribuída, penetração harmônica e endogênese: estudo de caso

Abstract

The constant growth in electricity demand, because of population growth and technological development, has resulted in the increase of the use of non-renewable resources over the years and irreversible environmental degradation. Thus, the growing concern of the electricity sector with the generation of energy from renewable sources, alongside with the degradation of the traditional model where the energy flow is unidirectional, results in a rapid increase in distributed generation, mainly as a source photovoltaic and wind energy. These distributed generation sources, which have an intermittent characteristic, use converters based on power electronics in which are connected to the network. Such converters do not insert purely sinusoidal currents into the electrical system, having some harmonic content. As the distribution systems are initially constituted for a unidirectional power flow, it is necessary to evaluate the perturbation in the energy quality in systems containing this new scenario. In this context, the main objective of this work is the study of the influence on the energy quality, within the scope of the harmonics, coming from the distributed generation. For this, the measurement method is used to evaluate the quality of the energy coming from the micro-grid installed in the building of the Post-Graduation in Electrical Engineering of the Federal University of Espírito Santo (UFES). The micro-grid is composed of distributed wind and photovoltaic generation. With the results, it is possible to analyze which type of distributed generation has greater variation of the generated harmonic levels, what periods of the day that most influence in the generation of harmonics and what is the relation between the power and the harmonic distortion rates generated by the distributed generations. development, has resulted in the increase of the use of non-renewable resources over the years and irreversible environmental degradation. Thus, the growing concern of the electricity sector with the generation of energy from renewable sources, alongside with the degradation of the traditional model where the energy flow is unidirectional, results in a rapid increase in distributed generation, mainly as a source photovoltaic and wind energy. These distributed generation sources, which have an intermittent characteristic, use converters based on power electronics in which are connected to the network. Such converters do not insert purely sinusoidal currents into the electrical system, having some harmonic content. As the distribution systems are initially constituted for a unidirectional power flow, it is necessary to evaluate the perturbation in the energy quality in systems containing this new scenario. In this context, the main objective of this work is the study of the influence on the energy quality, within the scope of the harmonics, coming from the distributed generation. For this, the measurement method is used to evaluate the quality of the energy coming from the micro-grid installed in the building of the Post-Graduation in Electrical Engineering of the Federal University of Espírito Santo (UFES). The micro-grid is composed of distributed wind and photovoltaic generation. With the results, it is possible to analyze which type of distributed generation has greater variation of the generated harmonic levels, what periods of the day that most influence in the generation of harmonics and what is the relation between the power and the harmonic distortion rates generated by the distributed generations.