Flow direction algorithm for optimal coordination of directional overcurrent relays considering arc flash

This paper presents a novel meta-heuristic optimization method called flow direction algorithm (FDA) to achieve optimal coordination of Directional Overcurrent Relays (DOCRs) while considering the impact of Arc Flash (AF). The coordination between relays plays a significant role in the protection scheme of modern power systems, and achieving it is one of the most important challenges facing power system engineers. There are impacts such as incident energy (IE) caused by arc flash (AF) which must not exceed the threshold according to IEEE 1584 and NFPA 70E standards to increase workers' safety and reduce the danger of equipment damage. The objective of this study is to reduce the overall operation time of primary relays under certain constraints and thus reduce the amount of IE . The FDA is designed to address the highly nonlinear optimization problem of DOCRs coordination. The decision variables of this optimization problem are considered as the time dial setting and the pickup current or the plug setting. The effectiveness of the FDA method is verified by comparing it with well-known methods such as Gravitational Search Algorithm, Imperialistic Competition Algorithm, Sine Cosine Algorithm, and Harmony Search Algorithm. The method was tested on 8-bus and 15-bus systems, showing substantial improvements in optimal coordination, with FDA successfully limiting the IE to 40 cal/cm2. The FDA outperforms the other algorithms, achieving improvements of up to 73.18 %.