Estudo de curto-circuito em uma unidade minigeradora fotovoltaica de 4 MW – estudo de caso

Abstract

Brazil has shown considerable growth in terms of distributed generation. ANELL, through guidelines, standards and with the aim of regulating the electrical sector, establishes categories based on the proposed generation, reaching up to 5 MW. However, with an increase in generating sources, the system topology changes, presenting greater operational complexity and security in the supply of electrical energy. Aiming to increase security in distributed generation, concessionaires require additional protections beyond the minimum ones determined by ANELL. With the objective of determining the fault currents of a 4 MW mini photovoltaic generator system connected to a 13.8 kV electrical grid in Tocantins, relevant technical information was collected about the substation, generation and connection of the consumer unit. Next, the generation system was modeled in the Anafas software in order to define the fault currents of the aforementioned generating unit. After adequate modeling of the system in the software, the short circuit study takes place in three distinct stages. In the first stage, involving obtaining the fault currents at the project's delivery point, the fault values are presented in all the project's buses, including the delivery point with the system operating. Finally, in the third and final step, a comparison of the increase in the short level at the delivery point is carried out.