| Title |
Protective Coordination Design of AC/DC Hybrid Urban Railway Power System |
| Authors |
조규정(Gyu-Jung Cho) ; 김형철(Hyungchul Kim) |
| DOI |
https://doi.org/10.5370/KIEE.2025.74.12.2033 |
| Keywords |
AC/DC hybrid power system; DC/DC converter; Fault analysis; Protection coordination; Urban railway |
| Abstract |
In this paper, we analyze the fault characteristics of an AC/DC hybrid urban railway power system utilizing next-generation power conversion equipment and propose a protective coordination scheme. Using Power System Computer Aided Design/Electromagnetic Transients Program including DC (PSCAD/EMTDC), we modeled the urban railway power system based on a 20/1.5kV insulated Modular Multilevel Converter (MMC) type DC/DC converter. We analyzed the fault current characteristics through simulated faults at five contingency fault locations. Based on the analysis results, a step-by-step protective coordination scheme for fault selection relays (50F) and reverse current relays (32D) has been proposed. It is verified that the fault propagation to healthy substations can be effectively prevented by adjusting the 50F for bus protection to 10ms and the 32D for backup protection to 20ms. |