Phase Balancing using Simulated Annealing

Deregulation eliminates the boundary of the territory of the monopoly power industry. Competition forces utilities to improve power quality as well as to reduce investment and operation costs. Feeder imbalance describes a situation in which the voltages of a three-phase voltage source are not identical in magnitude, or the phase differences between them are not 120 electrical degrees, or both. It affects motors and other devices that depend upon a wellbalanced three-phase voltage source. Phase balancing is to make the voltages balanced at each load point of the feeder. Phase swapping is a direct approach for phase balancing with the minimum cost. Phase balancing can enhance utilities’ There are two approaches for phase balancing. One is feeder reconfiguration at the system level; the other is phase swapping at the feeder level. Feeder reconfiguration has been extensively studied in the past several decades while phase swapping has been ignored. Since feeder reconfiguration is primarily designed for load balancing among the feeders, most researchers do not consider phase balancing as an objective in feeder reconfiguration. Only a few people incorporated phase balancing into feeder reconfiguration approaches based on the unbalanced feeder systems[3-6]. But they realized that feeder reconfiguration has limitation to reach phase balancing [3-6]. competitive capability by improving reliability, quality, and reducing costs. Therefore, phase balancing optimization is nowadays receiving more attention in the power industry, especially in today’s deregulating environments. The nonlinear effects, such as, voltage drops and energy losses, make the problem difficult to solve. This paper introduces Simulated Annealing as an effective method to solve a power distribution phase balancing problem with its non-linear