Backward Forward Sweep Algorithm for Unbalanced Three-Phase Power Flow Analysis in Distribution Systems Containing Voltage Regulator

Abstract

The distribution system has its own characteristics such as a high R/X ratio; has a radial or weakly meshed topology; or multi-phase system. Various studies have been carried out with different approaches to solving power flow in distribution systems to produce a robust and simple method, but the backward forward sweep (BFS) method remains the main choice mainly because of its simplicity. This study aims to validate the accuracy of the power flow algorithm in a distribution system containing a voltage regulator based on the BFS method. The process of compiling the algorithm is divided into 2 stages, namely the initial stage without involving a voltage regulator, and the next stage, the voltage regulator being involved in the power flow process. Furthermore, each step or stage of the power flow will produce a power flow output and the results will also be individually validated. The simulation results applied to the IEEE 37 node test system as a benchmark in conditions without a regulator, namely in phases AB, BC, and CA have a smaller maximum voltage magnitude difference of 30%, 40%, and 60% respectively when compared to the results of the other study, so that better results are obtained. Meanwhile, when the voltage regulator is involved in the power flow, the simulation results obtained in phases AB, BC, and CA have a maximum voltage magnitude difference with 1E-04, 1E-04, and 2E-04 respectively. This difference is so small that it gives confidence that the algorithm that has been compiled has high accuracy.