<p>The unified power flow controller (UPFC) is one of the most promising devices for load flow management in flexible AC transmission systems. Optimizing both the size and placement of UPFCs is crucial for enhancing the system's loading capacity. Additionally, the number of UPFCs connected to the system significantly influences the optimal placement process. Numerous optimization techniques have been proposed to address these challenges. In this paper, we introduce a novel hybrid algorithm, the butterfly with global search insisted Aquila optimization (BGI-AO) algorithm, designed for the optimal placement of UPFCs to achieve efficient power flow management. The proposed algorithm is the hybrid rendition of the traditional butterfly optimization algorithm and Aquila optimization algorithm. Furthermore, the total cost function presented in this paper for solving the placement problem involves power loss and cost minimization. The analysis was carried out on IEEE 5, 14, 30 and 57 bus systems, respectively, by connecting 2 and 5 UPFCs, and the results were obtained by altering the loads from 0, 20, 50, and 100. In terms of loss, voltage profile, and cost, the adopted approach is compared as well as proven to be superior to other standard methods.</p>