Power Quality Model of Distributed Networks Integrated with Renewable Energy Sources

Abstract

he integration of renewable energy sources (RES) into the power system distribution network have proven to be beneficial to all the power sector players. These include: reduced greenhouse gas emission, reduced transmission and distribution losses, delivery of clean power to consumers due to close proximity of loads to the generators, and deferred investments by distributed network operators. The continued integration of RES has been enhanced by inability of conventional energy to meet increasing power requirements, need for clean energy, low power generation costs due to technological advancements, and favorable government policies encouraging investment in renewable energy sector. This integration however, necessitates re-configuration of distribution network since RES cause reversed power flows, instability among other power quality concerns. This transformation will rely on studies conducted on the behavior of grids integrated with renewable energy sources. We examined the impact of integration of solar, wind and gas micro-turbine generators. on harmonics and flicker of low voltage (LV) and medium voltage (MV) networks. This was realized by integrating the RES at selected locations of the IEEE-33 bus system and carrying out harmonic and flicker analysis using DigSILENT Power Factory software. Results showed increased harmonic distortion and flicker levels on LV and MV networks dependent on the type, location, penetration level and whether a single-type of RES or combination of RES was installed.