Reverse Power Flow (RPF) Detection and Impact on Protection Coordination of Distribution Systems

Abstract

Due to the inclusion of distributed generation (DG) in modern power systems, there are certain changes in the distribution and transmission stage, either by impedance reflected by the lines, the increase of short-circuit currents, or the X/R relation, seen from the different nodes on the grid. Such changes have a direct impact on protection coordination, which is the priority of study in this article, but it is important to note that another characteristic affected by the DG is the power quality in terms of voltage sags, swells, and harmonics. One of the significant impacts due to the DG is the reverse power flow (RPF), which generally occurs when the generation of a distributed electric power plant exceeds the local load demand, causing power to flow in the opposite direction to normal. This phenomenon can be produced by the intermittency in the renewable energies, which depends on climatic factors. The consequences can be evidenced in the power system with voltage peaks; therefore, the sensitivity and various parameters of protection coordination are critically affected, which has further implications in the power quality. This work proposes a tool to identify possible scenarios of RPFs and a feasible solution is introduced. A comparative assessment is done to minimize the possibility of an RPF in the IEEE 13 Nodes radial system with conclusive results.