Voltage Control in Distribution Feeders with High Solar PV Penetration: Case Study for Different Approaches.

Abstract

Rising amount of distributed solar Photovoltaic (PV) power in distribution feeders is expected to impact the nodal voltage levels. This paper presents a case study of three different approaches – smart PV inverters with Volt-VAr functionality, on-load tap changers and battery systems to mitigate localized voltage issues. An actual 11 kV distribution feeder of a utility in Delhi, India has been extensively modeled, beyond the transformer secondary, incorporating the low-voltage 415 V network, to a certain extent, to present realistic voltage estimates. Load growth and solar PV capacity growth scenarios have been realistically designed to assist the utility in understanding the expected operational challenges of rising solar PV penetration levels. Distribution load-flow has been performed to estimate the voltage at different buses and to assess each mitigation technique. A practical estimate of the cost associated with each mitigation technique against the expected benefits has also been reported.