Análise comparativa do impacto, no nível de tensão da rede elétrica, da inserção de conversores de potência

Abstract

The generation of electricity using energy sources such as wind, solar, and biomass has become a reality due to the scarcity of fossil fuels and their increasing cost, environmental problems such as global warming and increased pollution air, as well as economic and political factors. Market growth and government incentives in several countries accelerate and encourage the development of the renewable energy sector. However, studies still need to be carried out to clearly identify the impacts that the insertion of these sources represents for the electric grid. Problems related to QEE, caused by disturbances in the electrical system are becoming more common as the GD is being inserted in the electric grid. The reduction of these disturbances can be done through the use of compensators in series, in parallel, or hybrids compensators. The series compensator is usually used in the compensation of voltage sags (voltage sags) and minimization of transient and harmonic voltages, while the parallel compensator guarantees the compensation of current harmonics, in the presence of non-linear loads. Thus, using the PSIM®

software, a study of the type of connection that must be made between the GD and the electric grid is presented, according to with equivalent impedance in the PAC, of the location of GD, and with levels of voltage variation that each connection is capable of mitigating, as well as aspects of the grid’s protection system. The model used presents 16 (sixteen) PACs, in which the PACs 3 (three), 7 (seven) and 13 (thirteen) are studied, located in a distribution grid of BT. Two (2) methods are developed to study the behavior of the voltage variation in the PAC as a function of the current amplitude (Im and the angle (θc) of the GD. The simulation was performed in a scenario of voltage variations of short duration, with the classification of momentary voltage variation and duration less than or equal to three seconds, within the range of 0.1 to 0.9 pu of the reference voltage (1pu). In this way, according to the PACs analyzed, the voltage levels that the appropriate type of connection can safely actuate are defined, ensuring the QEE and the reliable and safe operation of the system.