Análise do impacto da geração distribuída fotovoltaica com diferentes níveis de penetração em alimentadores de distribuição em média tensão utilizando OpenDSS

Abstract

This thesis does a study of the impacts and interactions between photovoltaic distributed generation and the medium voltage energy distribution system, through modeling using the software OpenDSS of the Agua Fria’s substation real feeder 01I2, located in Fortaleza-CE and owned by Enel Distribution Ceará. The distributed generation is an on-growth business, meaning that studies are needed in order achieve the best integration with the system. Through knowledge of OpenDSS’s syntax, a code builder script was made in Excel, using text concatening structures on a data base extraction, which models the medium voltage system and sets the case studies starting point. The study is divided in 5 distinct simulation scenarios with different levels of connected load and power injection through photovoltaic generations. Scenario 0, which is the normal grid state, whith no power injection;Scenario 1, which has 20% of the load`s total power as PV generations; Scenario 2, with 50% of the load`s total power as PV generations; Scenario 3, with 100% of the load`s total power as PV generations; Scenario 4, which has the same PV generation total power as Scenario 3, but only half of the original load. The following energy quality characteristics were analyzed: voltage levels throughout the circuit, power flow, power factor (PF) and the system’s technical losses. Also, were analyzed the new three, two and one phased short circuit levels for every bus, in order to compare the generator’s contribution for all scenarios. The power injection on moderate levels, as seen in scenarios 1 and 2, can bring lower stress condition to the system, improving energy quality on all aspects while raising slightly the short-circuit levels. However, higher levels of power injection during normal or light load conditions like scenarios 3 and 4 will cause a degradation on energy quality indicator’s, with higher short-circuit levels. That degradation occurs due to the generation exceeding load levels, which can cause reverse power flows, higher voltages and extra losses, affecting not only costumers but also many equipment connected to the grid.