Análise e estudo teórico de curto-circuito no barramento CC de uma usina fotovoltaica

Abstract

This present work deals with the proposition of a mathematical model that enables the calculation of the short-circuit current in the DC bus of a photovoltaic plant. Because with the legal framework of distributed generation in Brazil, it, led by photovoltaic generation, has been gaining great space and being increasingly integrated into the network, by the on grid system, a system that offers many advantages, either by reducing costs, either increasing the reliability of the system, or even improving the quality of electrical energy, but is notable that a massive increase in this type of generation in power systems will generate consequences, studying these consequences and understanding them can be very useful either for guaranteeing the safety of equipment and users, or for the formulation of technical norms aiming to guide the professionals who are designing that plant. Therefore, the proposition of this model was based on a literature review, seeking to satisfy two criteria, fidelity and simplicity, so the simple diode model was chosen, because it is quite trustworthy and simple. To confirm the model, a simulation was established using all the theoretical basis developed, in the SIMULINK software, which has tools capable of emulating every detail of the mathematical proposition, which had to be generalized in order to make it simple to simulate the array of 21 panels, in series, by 180 panels, in parallel, this arrangement taken from the diagram of a 3MW plant to be installed on the PICI campus, this arrangement indicates the third part of the plant's capacity, considering that 3 identical arrays, like this, will be installed. The analysis was based out through the load curve taken from SIMULINK itself, which has its own simulator for a photovoltaic array, and contrasting these data with the load curve generated through the proposed mathematical modeling. Therefore, the short circuit current that the plant will actually be exposed to is less than the rated current on the data sheet under test conditions.