Electric substations (ESS) are important facilities that must operate even under contingency to guarantee the electrical system’s performance. To achieve this goal, the Brazilian national electricity system operator establishes that alternating current (AC) auxiliary systems of ESS must have, at least, two power supplies, and in the case of failure of these sources, an emergency generator (EG) must at least supply energy to the essential loads. In order to improve the availability of auxiliary systems, a microgrid with other sources, such as photovoltaic (PV) systems and Battery Energy Storage Systems (BESS), can be an alternative. In this case, an economical optimization of the PV/BESS system must be addressed considering the costs associated with the installation and maintenance of equipment, and the gains from the credits generated by the photovoltaic system in the net metering scheme. In this paper, the size of the BESS system was determined to supply energy to the load of auxiliary systems of an ESS, as well as a PV system to achieve a null total cost. Furthermore, multi-objective optimization using the genetic algorithm technique was employed to optimize the size of the hybrid PV/BESS to minimize the investment cost and time when the demand was not met. Simulations under different scenarios of contingency were allowed to obtain the Pareto frontier for the optimal sizing of a PV/BESS system to supply energy to AC auxiliary systems in an ESS under contingency.

The power surges produced by lightning discharges affect the electrical network at residences and cause damages in home appliances. To avoid these damages, it is recommended to use Surge Protection Devices (SPD) in the power input of the appliances (SPD Class III). This article presents the current levels that the SPD Class III bypass at the entrance of the appliances. We show that the SPD can deflect 75% of the current that reaches it. We also show that SPD increase the voltage level supported by equipment in 2 kV or more and thus maintain the equipment's useful life. Cell phone chargers, laptop chargers and refrigerator power supply were submitted to a series of surges with different voltage levels to determine the number of surges that each equipment can withstand at a specific voltage. In all the studied equipment, SPD increased the number of supported surges.

Aplicação do Método dos Elementos Finitos na Eletrostática e Estimulação Magnética Transcraniana

Este artigo apresenta um design para modelar e construir um protótipo de um UAV quadrotor. Também são propostos alguns dispositivos elétricos e sensores a serem utilizados, mostrando suas características e necessidades no projeto. Para escolha dos dispositivos foram feitas comparações e estudos baseados em outros projetos.

Anais do Simpósio de Engenharia, Gestão e Inovação (2674-5526) - Classificação De Condução Veicular Por Árvore De Decisão E Floresta Aleatória Baseado Em Dados Veiculares E No Conceito De Direção Defensiva