Optimal protection coordination for directional overcurrent relays in radial distribution networks with inverter-based distributed energy resources

• Published in: International journal of electrical power & energy systems Vol. 167; p. 110622
• Main Authors: Li, Jie, Feng, Jingtong, Huang, Min, Liu, Shenquan, Wang, Gang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2025; Elsevier
• Subjects: Directional overcurrent relay; Inverter-based distributed energy resources; Multi-objective particle swarm optimization; Protection coordination; Radial distribution network; Directional overcurrent relay; Multi-objective particle swarm optimization; Protection coordination; Radial distribution network; Inverter-based distributed energy resources
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2025.110622

•The protection performance analysis in distribution networks.•A novel multi-objective optimal protection coordination model.•An improved multi-objective particle swarm optimization method.•A time–space section evaluation framework. The optimal setting of directional overcurrent relays ensures the reliable protection and fast fault clearance of radial distribution networks. However, the increasing proliferation of inverter-based distributed energy resources can result in protection coordination failure or high operating times of directional overcurrent relays in radial distribution networks. This paper investigates the adverse impacts of grid-connected inverter-based distributed energy resources that adopt the active/reactive power control strategy on the protection speed, sensitivity and selectivity of directional overcurrent relays in radial distribution networks. A multi-objective optimal protection coordination model is formulated, which incorporates the protection performance of directional overcurrent relays, operation conditions and economics that result from the inverter-based distributed energy resources and power grids. The Pareto-front of the proposed optimal protection coordination problem is obtained by the improved multi-objective particle swarm optimization, where a time–space section evaluation utilizes the K-means clustering method to improve the computational efficiency. Furthermore, an analytic hierarchy process and criteria importance through intercrieria correlation weights-based technique for order preference by similarity to ideal solution algorithm is proposed to determine the optimal directional overcurrent relay settings. The developed coordinated framework is applied to a radial distribution network with inverter-based distributed energy resources in MATLAB and PSCAD/EMTDC simulation. The comparative analysis is provided and the effectiveness of the proposed scheme is validated through extensive case studies.