Adaptive protection method with fault current limiting mechanism for directional over current relays coordination problem

Abstract

Coordination of Directional Over Current Relays (DOCR) is an important issue in the protection of power systems. In this paper, DOCR coordination, which has the problem of nonlinear and high constraints, is discussed The object function, reported in the literature, has been re-written by adding relay setting constraints multiplied by a weight factor to ensure optimum coordination of DOCRs. At first, the Evaporation Rate Controlled Water Cycle Algorithm (ER-WCA) and Harris Hawk Optimization (HHO) algorithms were used to compute the optimum coordination of the DOCR problem. The proposed algorithms are applied to the 9-bus test system. In addition, the results obtained using ER-WCA and HHO were compared with those obtained using other algorithms in the literature. Then, a new adaptive protection method, which adapts to changing power system conditions in power grids with Distributed Generation (DG) system, is proposed. In this new adaptive protection method, the HHO algorithm has been used to ensure optimum coordination of DOCRs. Also, in this new adaptive protection method, a structure with Fault Current Limiting (FCL) mechanism, which determines the critical fault point based on the both of the current and voltage index, is proposed in power systems. Then, by applying this new adaptive protection method to 10 bus Turkey distribution system, the effectiveness of the study was discussed. © 2022 Gazi Universitesi Muhendislik-Mimarlik. All rights reserved.