The impacts of distributed generation on fault detection and voltage profile in power distribution networks

Installing Distributed Generators (DG) in distribution networks brings many advantages such as improving voltage and power quality, mitigating voltage sags, improving transmission system congestion and providing more affordable capacity for utilizing renewable energy resources. All of those factors lead utility companies to integrate DGs into current distribution networks as much as possible. This integration benefits both customer and utility sides. However, this incorporation will change the radial distribution networks fundamental aspects, i.e. upstream or Utility Grid (UG) feeding, passive feeders and fault current path. Hence, suitable measures should be taken before this integration to avoid losing system reliability and security. This study investigates consequences of DGs integration into the current distribution networks such as bus voltage profile and fault current level and contribution. This investigation paves the way toward categorizing varied DG integration effects on distribution networks protection schemes miscoordination or switchgear malfunctioning. Four different types of DGs have been employed in three scenarios with different penetration levels. Different DG types enable us to investigate the DG interconnection impacts on fault current characteristics and sharing. The study was carried out on the IEEE industrial distribution network.