Linear Programming Coordination for Overcurrent Relay in Electrical Distribution Systems with Distributed Generation

• Published in: Applied sciences Vol. 12; no. 9; p. 4279
• Main Authors: Alcala-Gonzalez, Daniel, García del Toro, Eva M., Más-López, M. Isabel, García-Salgado, Sara, Pindado, Santiago
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-05-2022
• Subjects: adaptive protection; Coordination; Distributed generation; distributed power generation; Electric fuses; Electric power; Electric power distribution; Electric relays; Electrical transmission; Genetic algorithms; Linear programming; Optimization algorithms; Overcurrent; power distribution; Power flow; power system protection; Protection systems; Response time; Substations
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app12094279

Electric power distribution networks are generally radial in nature, with unidirectional power flows transmitted from the highest voltage levels to the consumption levels. The protection system in these distribution networks is relatively simple and consists mainly of fuses, reclosers (RC) and overcurrent relays (OCRs). The installation of distributed generation (DG) in a network causes coordination problems between these devices, because the power flows are no longer unidirectional and can flow upstream to the substation. For this reason, the work proposed here analyzes the most significant impacts that DG has on the protection devices and proposes an adjustment method for the OCRs based on linear programming (LP) techniques with the aim of improving their response time to the different faults that may occur in the main feeder of the network. The distribution system selected for the study is the IEEE 34 bus system using DIgSILENT 14.1 software for its modeling and Matlab for the adjustment of the overcurrent devices. Results indicate that better coordination between protection devices are achieved if LP is used.