Análise dos impactos da inserção de uma usina solar fotovoltaica de 2 MW na rede de 13,8 kV do Campus do Pici

Abstract

The accelerated expansion of distributed generation (DG), especially through photovoltaic plants, has caused significant transformations in electrical distribution systems. Although it brings advancements such as diversification of the energy matrix and reduction of technical losses, this integration also imposes complex challenges to protection engineering, particularly regarding changes in short-circuit current levels and selective coordination of protection devices. In this context, this work analyzes the effects of connecting a 2 MW photovoltaic plant to the 13.8 kV network at the Pici campus of UFC. The choice of power and voltage level is based on the criteria of ANEEL Normative Resolution No. 1000 and Enel Technical Standard 122, which regulate the connection of distributed generation in medium-voltage networks. Through simulations carried out in the MATLAB Simulink environment, fourteen different scenarios were evaluated, including situations with and without distributed generation, considering different points of connection of the plant in a three-phase system. The results indicate that the plant’s connection leads to a reduction in three-phase, two-phase, and single-phase short-circuit currents, with decreases of up to 700 A measured at analysis points. This reduction directly affects the settings of ANSI 50/51 protection functions, impacting the operating times of reclosers, which in some scenarios showed reductions of up to 1.8 seconds. In certain cases, such changes result in loss of coordination between protection devices, while in others coordination is maintained. This behavior highlights the direct influence of the generator’s location on the selectivity and operating time of protections. Therefore, the study reinforces the importance of careful planning for the safe and efficient integration of distributed generation, providing essential technical insights for the development of more resilient networks amid the growth of renewable sources.