Strategies to mitigate reverse power flow in distribution networks with high penetration of solar photovoltaic generation

Abstract

The power industry has undergone significant recent changes due to the growing demand for a cleaner and more sustainable energy mix. In this context, the Brazilian government began encouraging distributed generation (DG), making photovoltaic generation a strong trend in the country. However, the expansion of DG may cause negative impacts on the grid, such as reverse power flow (RPF) and overvoltages, which motivates research aimed at mitigating these effects. This study proposes strategies to mitigate RPF in distribution networks with high penetration of photovoltaic generation and evaluates their impacts on the electrical system. Three strategies were analyzed: a battery energy storage system (BESS), a control mechanism using a Grid Zero inverter, and PV Curtailment. The strategies were implemented in OpenDSS on a real distribution network located in São Paulo, Brazil. The assessment involved analyzing power flow in critical transformers and at the substation, as well as monitoring bus voltages and network energy losses. The quantitative results demonstrate that BESS allocation was the superior strategy, reducing technical losses by 61.3% and fully mitigating reverse power flow under steady-state conditions. The Grid Zero inverter eliminated power injection into the grid; however, it increased substation dependency by 59% compared to the baseline scenario. PV curtailment, although achieving the smallest reduction in RPF, proved to be the most effective technique for power quality, limiting the average voltage rise to 0.7%.