Paper Title
Optimum Capacitor Allocation in three Phase Unbalanced Radial Distribution System with Harmonics and Resonance Consideration using PSO Algorithms

Abstract
Distribution system connects between generation system and transmission system to the load. Power quality in distribution system can affect the flow of electric distribution. Decrease in power quality can be caused of low power factor, voltage drop, line loses and harmonic. Installation of capacitors can overcome the power quality problems when placement is appropriate. In a distorted system the presence of a capacitor may aggravate the harmonic level and cause either parallel or series resonance. In this research, capacitor placement and capacities are limited by minimum voltage, maximum reactive power load, THD and resonance index. Resonance index based on limit of capacitor loading according to IEEE standard. This scheme is tested on a distorted three-phase unbalanced distribution system which is have under voltage characteristics. The simulation result shows the installation of capacitor using PSO algorithm by considering harmonics and resonance index is capable to fulfill standard of THD that is 4.6929 % and decrease of active power loss equal to 19.74% and minimum voltage 0.95 pu. Keywords - line loses, resonance index, THD, PSO.