Estudo de estabilidade de tensão em sistemas de distribuição com alta penetração de geração distribuída

Abstract

The growing use of distributed generation (DG), especially photovoltaic, as a way to supply the world demand for electricity has brought challenges in the planning and maintenance of electrical distribution systems. The possibility of allocation at different points in the network and the variability of the generation capacity brings several impacts, including the levels of voltage stability. In this work, an analysis of the voltage stability will be done using the balanced IEEE A13N and A34N feeders with the insertion of distributed photovoltaic generation at different penetration levels. Some technical aspects were analyzed, such as the generation capacity and the location of the distributed generation using the voltage stability index called V/Vo. This method is simple to calculate, but it is able to identify the most unstable bus of the analyzed feeders while the penetration levels of the distributed generation were increased. With this, it was possible to draw up a ranking of the buses, from the most stable to the least unstable, as the feeders were modified with the insertion of the DG. It was also possible to identify, through the same index, if the location of the distributed generation was able to influence the voltage stability levels. To corroborate the use of the V/Vo index, PV curves were generated for the A13N feeder, in order to compare the results obtained with both analyses. It was found that, in general, there is an improvement in the voltage stability margin with the insertion of distributed generation in the system, however, in some cases the high penetration resulted in voltage instability and/or overvoltage in the electrical system. The location of the generator can considerably influence the voltage stability levels of the feeders. GD connection on originally more unstable buses brings greater benefits to the system, when compared to connection on more stable buses. Furthermore, when connected to some bars, GD can cause voltage instability to the entire feeder.