Fault isolation and reconfiguration in a three-zone system

This paper provides experimental verification of a fault isolation sequence in a DC Zonal Electrical System. Three electrical zones consisting of phase controlled rectifier interfaces to medium voltage AC distribution, two DC distribution buses and downstream converters, inverters feeding loads are energized and bolted faults are applied to various locations. The Fault Isolation and Reconfiguration approach utilizes no load switches for fault isolation aided by de-energization of the affected buses. Three electromechanical no load switches in a single assembly are utilized at the interface between electrical zones. The instantaneous peak fault currents were captured at each switch and sent to adjacent modules over a Ethernet-based Local Area Network in order to locate and isolate the fault to the nearest bus segment. Experimental results show that in most cases full output capacity was restored autonomously. Loss of communications scenarios are tested showing limited power restoration.