Abstract: The present invention relates to a method of generating fault indication in a feeder remote terminal unit for a power distribution automation system. The method is performed in a distribution system that includes a plurality of feeder remote terminal units, which are installed in respective sections of a line and are configured to measure voltage, current and a phase difference of the line, and a central control unit for determining whether a fault occurs and controlling operation of the feeder remote terminal units. In the method, phases are measured by each of the feeder remote terminal units. The phase of a zero-sequence current is compared with that of a zero-sequence voltage. A direction of a fault current is calculated, and fault indication information is generated in the calculated direction of the fault current.

Abstract: Disclosed is a fault diagnosis device for diagnosing a fault in a bay Intelligent Electronic Device (IED) for a substation automation system, which includes an online IED diagnosis device and a backup IED. The online IED diagnosis device includes an IED selection unit, an IED switch unit, a fault diagnosis, and a result display unit. With reference to a Substation Configuration Description (SCD) file, the online IED diagnosis device designates an IED to be tested, and extracts backup information for the IED to be tested. A backup IED replaces the operation of the IED to be tested based on the extracted backup information. Further, the online IED diagnosis device determines the occurrence or non-occurrence of a fault in the IED to be tested by analyzing response information received in response to transmission of a test pattern to the IED to be tested.

Abstract: A DC power transmission system of a voltage source converter using a pulse-interleaving auxiliary circuit is disclosed. The converter system of the present invention comprises an IGBT converter for converting an AC power to a DC power or the DC power to the AC power; an open Y-Y transformer and a Y-? transformer for stepping up or stepping down the AC power having a predetermined magnitude; a capacitor for dividing a DC voltage; and a transformer and a half-bridge auxiliary circuit for overlapping a pulse type input voltage to increase a number of pulses of an output waveform. In accordance with the present invention, the normal transformer is used instead of a tapped transformer to reduce the size thereof and to obtain an accurate transformer ratio, the 3-level half bridge is used instead of the H-bridge to reduce the switching loss in order to increase the number of pulses of the output waveform by superposing the voltage in the form of the pulse using the auxiliary transformer and the bridge circuit.

Abstract: The present invention provides method for locating a line-to-ground fault point of an underground power cable system wherein a distributed parameter circuit analysis theory is employed to consider a capacitive element of a cable in a underground power cable analysis, thereby providing an accurate estimation of the fault distance even when the arrangement of the cable and the fault resistance are varied.