Harmony search approach for optimal capacitor placement and sizing in unbalanced distribution systems with harmonics consideration

In Radial Distribution Systems (RDS), the injection level of harmonics by non linear loads is high, due to continuous penetration of harmonic producing loads. Shunt capacitors play a vital role in enhancing the performance of Radial Distribution Systems. Introduction of shunt capacitors may further increase the harmonics, if not placed at optimal locations. This paper aims to identify optimal placement and rating of capacitors to reduce the cost of total real power loss and that of shunt capacitor installation cost while satisfying operating and power quality constraints by using Harmony Search Algorithm (HSA), which is relatively a new meta-heuristic method. The total cost of real power loss is considered as objective function, subject to the constraints of voltage profile and Total harmonic distortion level (THD). The backward / forward sweep technique based Radial distribution power flow (RDPF) algorithm and harmonic power flow (HPF) algorithm are implemented for power flow simulation. The performance of the proposed Harmony search algorithm (HAS) is tested on the standard IEEE 13 bus unbalanced radial distribution systems.