Influência da Intermitência Solar na Vida Útil do Sistema de Armazenamento em Microrredes Isoladas Baseadas em Geração Fotovoltaica.

Abstract

Storage systems have a significant portion of the total O&M costs in isolated microgrids with renewable sources, leading to strong investments in research on procedures, methods, and technology that lead to the preservation of the lifespan of such systems. Lead acid batteries continue to dominate this type of applications; however, their lifespan is strongly impacted by the usage regime. The intermittence in renewable sources in isolated systems requires the use of storage systems, however, this phenomenon is the main cause of premature aging of the batteries. In general, the effect of short-term flickering is neglected in studies with acid-lead batteries. This work investigates the impact of this variation of daily solar radiation on the useful life of a storage system based on acid lead batteries. From real data, four scenarios are constructed: the first one represents the best measured day, being considered the practical "ideal" day; the second, representing an intermediate scenario; the third, days with a high incidence of passing clouds, causing significant short-term intermittence. In the fourth and last scenario, a sensitivity analysis is performed, combining the previous cases with a weighting factor. The simulations are carried out using data from the real microregion of Ilha Grande - MA, with the bank charge/discharge process represented by the Schiffer model with an equalization period of 7 days. The results show that short-term intermittence has a significant impact on the Bank's lifespan. Ignoring this effect leads to errors in battery life estimates. The effect of the solar day type is also analyzed and discussed. In addition, a procedure is suggested to identify the most appropriate value for the equalization frequency of the storage system.