Journal of Computational and Theoretical Nanoscience

Enhancing the power transfer capability of transmission lines in a power system network has become
a critical concern, particularly as modern power systems grow in size, complexity, and energy demand.
The introduction of Flexible Alternating Current Transmission System (FACTS) technology provides
an alternative approach to improving power system performance. Among various FACTS devices, the
Unified Power Flow Controller (UPFC) stands out as the most versatile due to its ability to regulate
voltage magnitude, phase angle, and line impedance. To maximize the benefits of a FACTS device,
determining its optimal location and size is essential. This study employs the Voltage Sensitivity Index
(VSI) method to identify the best placement for the UPFC, while the Bat Algorithm (BA) optimization
technique is used to determine its appropriate size. The proposed approach is tested on the IEEE 14-
bus network, demonstrating a reduction in active and reactive power losses from 13,593 MW and
56,910 MVAr to 13,491 MW and 22.5715 MVAr, respectively. Additionally, the maximum bus voltage
improves from 1.0466 pu to 1.0626 pu (a 1.53% increase). The obtained results are further compared
with similar studies in the literature. Future studies should explore hybrid FACTS device, real time
optimization algorithms and stability for larger grids, considering dynamic condition and renewable
energy integration