Reverse Power Flow Analysis in Distribution Network

Distributed generation (DG) including small hydro generation, solar PV generation and bio energy installed in a certain distribution network area has led to a condition which power generation by DG within the distribution network is more than the local consumption. The condition where DG generation has excess and power flows from the distribution network back to the grid is referred as Reverse Power Flow (RPF). In this paper, an analysis of RPF has been conducted focusing on a selected distribution network with a total capacity of 20MW mini-hydro generation installed to the substation. By utilizing DigSilent simulation software, a base case study has been analyzed and a base case simulation network model was then validated by comparing the simulation results with the historical data from SCADA. Based on the validated network simulation model, several case scenarios have been studied where the capacity of the installed DG into the distribution network were increased. The impact of RPF on voltage profile at 11kV bus, transformer tap change occurrence, transformer losses and distribution network losses has been analyzed in all scenarios and the results were then presented.