S.Vimalraj1Dr.P.Somasundaram
Unlike traditional AC distribution systems, protection has been challenging for DC systems. Multiterminal DC power systems do not have the years of practical experience and standards that AC power systems have. Also, the current power electronic devices cannot survive or sustain high magnitude faults. Converters will shut down to protect themselves under faulted conditions. This makes locating faults in DC system difficult and causes the DC bus to de-energize. A fault protection algorithm for low-voltage DC-Ring bus microgrid system is presented in this paper in order to resolve the above issues. The main objective of the proposed method is to detect and isolate faults in the dc ring bus system without de-energizing the entire system and identifying the fault location. A non-iterative fault-location technique using a probe power is also presented in this paper. This probe power can also be used for a pilot test before main CB reclosing to avoid system issues that can be expected when the reclosing fails due to a permanent fault. The proposed concepts have been verified by OrCAD/Pspice simulations