Fault simulation studies of single-line faults in a delta-delta connected distribution system

Single-line faults in delta-delta connected distribution systems normally draw very low fault currents and cannot be detected by the usual overcurrent protective devices. The ground alarm relays that are used in this type of system can detect most ground faults but can neither identify the faulty feeder nor classify the fault type, nor detect open conductor faults. This paper describes an exhaustive simulation study, which will provide criteria for the detection and identification of single-line faults in a delta-delta connected distribution system. The conclusion is, that for single-line faults with no intermittent contact, criteria can be obtained, which can be used for detection and identification of single-line faults (including open conductor faults)