The radial distribution systems (RDS) commonly used around the world has the following disadvantages. First, when the DL is operated on a radial system, the line utilization rate is usually kept low. Second, if a fault occurs in the radial DL, a power outage of 3 to 5 minutes is occurring depending on the operator's proficiency and fault situation until the fault section is separated and the normal section is replaced. To solve this problem, Various methods have been proposed at domestic and foreign to solve this problem, and in Korea, research is underway on the advanced system of operating multiple linked DL always. A system that is electrically linked always, and that is built to enable high-speed communication during the protection coordination is named networked distribution system (NDS). Because the load shares the DL, the line utilization rate can be improved, and even if the line faults, the normal section does not need to be cut off, so the normal section does not experience a power outage. However, since it is impossible to predict in which direction the fault current will flow when a failure occurs in the NDS, a communication-based protection coordination is used, but there is no backup protection coordination method in case of communication failure. Therefore, in this paper, we propose a protective cooperation method to apply as a backup method when communication fails in NDS. The new method is to change TCC by location of CB using voltage drop in case of fault.
This research was supported by Korea Electric Power Corporation under "Development of Networked distribution system(R20DA24)".
참고문헌
M.-C.Alvarez-Herault, N.N'Doye, C.Gandioli, N.Ha-djsaid and P.Tixador, "Meshed distribution network vs reinforcement to increase the distributed generation connection," Sustainable Energy, Grids and Networks, Volume 1, pp.20-27, March 2015, [ https://doi.org/10.1016/j.segan.2014.11.001].
Bin Li, Xuan Yu and Zhiqian Bo, "Protection schemes for closed loop distribution network with distributed generator," International Conference on Sustainable Power Generation and Supply, Nanjing, China, April 2009, [10.1109/SUPERGEN.2009.5348370].
F. Belloni, R. Chiumeo, C. Gandolfi and M. Brenna, "Application of back-to-back converters in closed-loop and meshed MV distribution grid," AEIT Annual Conference - From Research to Industry: The Need for a More Effective Technology Transfer (AEIT), Trieste, Italy, Sept. 2014, [10.1109/AEIT.2014.7002023].
Sadegh Jamali and Hossein Borhani-Bahabadi, "Non-communication protection method for meshed and radial distribution networks with synchronous-based DG," International Journal of Electrical Power & Energy Systems, Volume 93, pp. 468-478, December 2017, [https://doi.org/10.1016/j.ijepes.2017.06.019].