Statistical analysis of photovoltaic distributed generation penetration impacts on a utility containing hundreds of feeders

Abstract

The increase in the number of consumers who produce part of their own electricity through photovoltaic distributed generation (PVDG) led to the need for studies on how the power system is affected. As the distribution systems were not designed to integrate PVDG, it is important for regulatory agencies and utilities to identify technical problems in the grid associated with the levels of photovoltaic penetration. In this regard, this study presents a method with indicators that quantify the technical impacts that PVDG growth causes to an actual utility that contains hundreds of feeders with different topologies, load types, and densities. Real solar irradiance and temperature values over a year, and photovoltaic system locations varying based on the Monte Carlo method were also considered in the computational simulations. This study helps the utilities to plan preventive measures to strengthen the grid, and regulatory agencies to enhance policies to support PVDG. We analyzed the impacts on voltage magnitudes, technical losses and peak demand arising from the PVDG integration. The results show that, even at low penetration levels (2%), one-third of feeders required modification in the distribution system to allow photovoltaic integration. For over 60% of feeders, penetration levels of up to 20% reduced technical losses and voltage problems, with practically no effect on peak demand. Feeders in residential and commercial/industrial areas presented increases in technical losses and voltage levels for high penetration levels. Rural areas presented reductions in these parameters for all levels of PVDG integration.