PERFORMANCE COMPARISON OF PSO, HGSO, AND DE OPTIMIZATION TECHNIQUES FOR COMPUTATION OF DIRECTIONAL OVERCURRENT RELAY COORDINATION IN POWER SYSTEMS

Directional over current relays (DOCRs) have been in use for ensuring the complete protection of the power system network. However, the modern power system is getting complex with the increased penetration of Renewable Energy Source (RES) based distributed generators (DGs), as the current flow become bidirectional. Hence, the system demands faster operation of the protection devices to prevent any major outages. Optimal values of all the DOCR settings viz, TDS and Ip need to be found out such as to minimize the overall time of operation of all the relays in the network. This study focuses on the comparative study of the optimization problem carried out using the prominent optimization algorithms - Particle Swarm Optimization (PSO), Henry Gas Solubility Optimization (HGSO) and Differential Evolution (DE). The ability of techniques is established on IEEE 6 - bus & WSCC 9 - bus test systems for mid-point line faults. The Protection Coordination Problem (PCP) is formulated as non-linear programming (NLP) problem, and the optimal settings of the relays TDS and Ip are achieved using MATLAB R2021a platform and validated the results in POWER WORLD simulator software. The results depict that the HGSO method shows a significant reduction in relays' time of operation compared to PSO, but DE gives superior results compared to other techniques with a minimum computational time.