Distributed Generation in Brazil: Regulatory Evolution, Expansion, and Technical Impacts on Distribution Networks

In recent years, distributed generation (DG) has expanded substantially in Brazil, driven by technological advances, declining installation costs, and regulatory measures that have created favorable conditions for its integration into the electricity sector. Despite its benefits, this expansion has introduced technical and regulatory challenges for distribution networks. Therefore, this study examines the evolution of the Brazilian DG regulatory framework, the growth of micro- and mini-distributed generation (MMDG) from 2015 to 2025, and the effects of photovoltaic DG on distribution network operation. The analysis combines a review of regulatory milestones and national energy statistics with power flow simulations performed using OpenDSS and MATLAB on a 136-bus distribution system. The simulations consider different DG penetration levels, installation locations, DG coverage, and inverter power factors. The regulatory analysis shows how Brazil's framework evolved to address grid connection requirements, electricity compensation mechanisms, and network operation. Furthermore, during the period examined, MMDG installed capacity increased from 16.5 MW in 2015 to approximately 45 GW in 2025, with photovoltaic systems accounting for 99.3% of the total. Regarding the technical impacts of DG, the simulations demonstrated that penetration levels, installation locations, DG coverage, and inverter power factors influence voltage profiles and active power losses. Distributing DG along the feeder contributed to reducing active power losses, while reactive power injection further reduced losses and voltage deviations. At 100% penetration, active power losses decreased from approximately 325 kW without DG to 26 kW with reactive power support. However, at higher penetration levels, losses increased under certain conditions, and reverse power flow occurred. These findings highlight the importance of considering network characteristics, DG allocation, and inverter operating conditions in connection assessments and distribution system planning.