Improved Phasor Particle Swarm Optimization with Fitness Distance Balance for Optimal Power Flow Problem of Hybrid AC/DC Power Grids

The optimal power flow of the hybrid AC/DC power grids including voltage source converter (VSC) based multi-terminal high voltage direct current (MTHVDC) links is a popular real-world engineering problem which optimal solution has been investigated. Due to the constraint and objective functions of this power system planning problem, the high geometric complexity of the search space in which it is defined makes it difficult to find the global optimum solution for this problem. This requires the development of an efficient meta-heuristic search algorithm for optimizing the optimal power flow problem involving hybrid AC/DC electrical networks. In order to solve the proposed problem, a comprehensive study has been conducted on the recently developed phasor particle swarm optimization (PPSO) algorithm, which has strong features. For this purpose, the search capabilities of PPSO were analyzed based on the problem and according to the results of the analysis, PPSO’s search operators were redesigned to meet the requirements in the search space of the power system planning problem. In this process, fitness-distance balance (FDB) method was used for the selection of solution candidates that guided the search process in PPSO, and two FDB-based PPSO variations were developed. The performances of the developed variations were tested, and the most effective ones were determined. The proposed FDBPPSO algorithm has been applied to the solution of the optimal power flow problem in hybrid AC/DC power systems as well as unimodal, multi-modal, hybrid and composition type problems in the CEC 2020 test suite. According to the results obtained from the experimental studies, determining the positions of the particles using the FDB-based guide mechanism improved the exploration and balanced search capabilities of the PPSO. Thanks to this improvement, effective solutions were found for the proposed power system planning problem and presented to the literature for the first time.