Alex Sandria Jaya Wardhana, Moh. Khairudin, Rustam Asnawi
High penetration of inverter-based generation (IBG) reduces fault current magnitude and compresses coordination time intervals (CTIs), challenging inverse-time overcurrent relay (OCR) selectivity in interconnected distribution systems. This paper proposes a robust IBG-aware OCR coordination framework based on a Modified Bat Algorithm (MBA) integrating adaptive CTI reinforcement and feasibility-preserving repair. The method is validated on a modified IEEE 13-bus interconnected network with 13 main-backup relay pairs. Under identical constraint-handling protocols, MBA achieves the lowest mean objective value of 0.739, outperforming nine benchmark algorithms, with improvements ranging from 13% to 35%. Wilcoxon signed-rank tests confirm statistically significant superiority (p<0.001, r>0.71). CTI compliance analysis confirms full coordination across all 13 relay pairs, with coordination margins ranging from 0.011 to 0.533 seconds above the minimum threshold. The obtained CTI values range from 0.311 s to 0.833 s demonstrating reliable selectivity maintenance even under inverter-limited fault current conditions throughout the interconnected network topology. © This article is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. License details: https://creativecommons.org/licenses/by-sa/4.0/
Electrical Engineering Education Department, Faculty of Engineering, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia; Doctoral Program on Engineering Science, Faculty of Engineering, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia
