Desenvolvimento de metodologia para análise decisória de inserção de geração fotovoltaica distribuída e armazenamento de energia interligada ao sistema elétrico de potência

• Autor(a) principal: Toledo, Olga Moraes
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/684
• topic: Energia solar fotovoltaica; Armazenamento de energia; Sistema elétrico de potência; Solar energy photovoltaic; Energy storage; Energy grid; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA

It is estimated that in the world today, especially in sub-developed or developing countries, roughly one and a half billion people do not have access to electricity. In a society, the lack of a reliable energy source for all, especially electricity, indicates an imbalance in living conditions. This inequality causes a lack of opportunity for development and consequently a migration to large cities. Insertion of distributed generation in the electricity system and more recently the insertion of different energy storage methods are being studied as an alternative for planning the electric expansion. Distributed generation with energy storage connected to the electricity system is an option for attending low-income populations and also when considering improvement of the load factor in order to allow expansion of the grid. Within this scope, the problem of distributed generation insertion and recently, energy storage has become of vital importance for usage optimization of these resources. In this work, a methodology is proposed to establish a general index focused on the insertion of distributed photovoltaic generation and energy storage in batteries for rural consumers. For validation of this methodology, an IEEE 14 bus electric power system with load variation for different energy providers was used for a period of one year. Real data were provided for rural energy consumption by the local electricity provider CEMIG for this study, and the insertion of different photovoltaic generation and energy storage was simulated to analyze the impact on the system in general, evaluating the best location for the different configurations and weights. This index is composed of five simple sub-indices classified according to three aspects: IG=f1(technical aspects)+ f2(economic aspects)+f3(environmental aspects), with different weights attributed to each criteria. The technical aspects were addressed by the following indices: voltage (IPT) and reliability profiles (IC). The economics aspects are whose which affect capacity of reliable energy supply by the grid, thus representing the increase in grid capacity were evaluated by means of the following indices: line losses (IPL) and load factor (IFC). Lastly is the environmental aspect, indicated by the environmental index (IAMB), which considers the reduction in greenhouse gas emission in function of the insertion of renewable sources. The index IG is directly proportional to the sum of the indices in which the positive response of the system represents an increase and inversely proportional to the sum of the indices in which a positive response of the system represents a reduction. Results of the simulation allow for evaluation of the best location for distributed photovoltaic generation and/or energy storage in a real electric power system. The simulation was performed in five of the fourteen busses of the IEEE 14 bus system, which represents the busses from which the radial branches originate, as supply lines to rural consumers. An hourly analysis was performed using demand data and generation variables, 24 hours for each typical month of the year, for three cases with different relations between photovoltaic generation and energy storage (only storage case 1; lowest level of photovoltaic generation and storage case 2; and highest level of photovoltaic generation and storage - case 3). These cases were defied by the optimization done a priori for each case simulated. To solve the power flow problem the Newton-Raphson method was utilized in the MatPower® program together with software developed in the MatLab® environment to determine the results. The objective was to encounter a set of photovoltaic generation arrays with energy storage which induce the best performance of the analyzed distribution network, optimizing each technical aspect according to the interest of the electricity distribution service. A results matrix was generated permitting the planning of different energy supply strategies. The proposed methodology was validated, thus allowing the planner to simultaneously visualize different aspects by means of a single index which includes the technical, economic and environmental aspects.