Análise do impacto da adição de postos de carregamento para carros elétricos em sistema de distribuição de energia elétrica

Abstract

This paper presents an analysis of the performance of an IEEE 4-bus balanced D-Y electrical distribution system following the addition of an electric vehicle load. The methodology was based on computer simulations. Initially, the system was evaluated in its original condition, revealing a low power factor and critical voltages on bus N4. To address these limitations, a 100 kvar three-phase capacitor bank was installed, resulting in a significant improvement in the voltage profile and correction of the overall power factor to values close to unity, thereby establishing the base case for the study. Next, the insertion of a ZIP load representing the typical behavior of an electric vehicle was simulated. The results showed a critical voltage drop in one of the phases of bus N4 (0.822 pu), overvoltage in other phases (up to 1.185 pu), increased reactive demand, elevated current values, and worsening imbalance indices (%I2/I1 = 12.8% and %I0/I1 = 5.1%). Thus, the insertion of the ZIP load representing the electric vehicle imposed new operating conditions on the system. To mitigate these effects, distributed generation (DG) was adopted as a solution by incorporating a constant power source equivalent to a photovoltaic unit. The simulation results showed that this strategy was effective in certain respects. The minimum voltage profile on bus N4 was raised to 0.921 pu, reducing the risk of undervoltage previously observed (0.822 pu). In addition, the overall and local power factor was corrected to values close to the regulatory limit of 0.92, notably for transformer T1 and line LINE2, both operating around 0.9234. It is concluded that the integration of electric vehicles into distribution systems requires careful planning and additional mitigation strategies, such as grid reinforcement, voltage control, and smart load management. The study demonstrates the importance of simulations to anticipate the impacts of these new demands and inform technical decisions that ensure the safe and efficient operation of the electrical system.