A Simple Method for Optimal Capacitor Placement in Unbalanced Radial Distribution System

Abstract

This article presents a simple method for investigating the problem of contemporaneously choosing optimal location and size of shunt capacitors in three-phase unbalanced radial distribution systems. The main objective function formulated consists of two terms: cost of energy loss and cost related to capacitor purchase and capacitor installation. The problem of choosing optimal locations and sizes for shunt capacitors in an unbalanced radial distribution system is addressed with the two algorithms in this article—one is for selecting the best locations of capacitor placement and candidate node identification algorithm; the second is for the sizing of capacitors, a variational technique algorithm according to available standard size of capacitors. The objective function used in this article is to maximize the net savings in the distribution system. This article presents the results of simulations for 25-bus and IEEE 37-bus unbalanced radial distribution systems.

Keywords:

• capacitor placement
• cost function
• power loss index
• power loss reduction
• unbalanced radial distribution system

Notes

^a Total active power loss is calculated after compensating Q _C at each node in all phases equal to local reactive load at that particular node.

^a Total active power loss was calculated after compensating Q _C at each node in all phases equal to local reactive load at that particular node.