Reliability Assessment of Protection System for DC Ring Microgrid Using Fault Tree Method

Abstract

This paper suggests a protection scheme for DC ring Microgrid (MG). Then, the reliability of this protection scheme is analyzed using the Fault Tree (FT) method. The reliability of the protection system is represented using Mean Time To Failure (MTTF) reliability index. Based on this reliability index, engineers can anticipate the reliability of the overall system. In this process, the importance of the system components influencing the overall system reliability is calculated using the time interval method. For the suggested protection system, results show that the MTTF for the overall protection system equals 2155.23 hours. In addition, the cable protection system is shown to have the most important protection function while diesel generator protection has the lowest one.