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Locating high-resistance grounding faults poses a tough and challenging problem for the safety of DC railway systems. High-resistance grounding fault current isn't sufficient to trigger switches, which may expand the accident or turn into potential hazards. In order to overcome the limits of the existing methods (such as signal injecting method, resistance method and so), developing a novel fault...
This paper presents the measured impedance at the relaying point in the presence of Static Var Compensator (SVC), one of the shunt connected Flexible Alternating Current Transmission System (FACTS) devices; in the case of inter phase, phase to phase and three phase, faults. The presence of SVC on a transmission line has a great influence on the measured impedance at the relaying point. In the presence...
This paper presents the results of the analysis of a vast fault records database. The fault records were obtained during numerous experiments performed from 2005 to 2011 in real resonant-earthed distribution networks. The purpose of these experiments was to provide data either for verifying distribution network safety during earth faults or for testing methods of earth fault location or elimination...
Distribution system operator (DSO) sometimes needs to operate the large network which means operating of the network with big capacitive current (in Czech Republic more than 800A). This operation puts the emphasis not only on the setting of the earth fault relays but on the safety of the point of fault too. The paper describes the theoretical analysis, simulation and tests in real compensated distribution...
This paper deals with line protection challenges experienced in system having substantial wind generation penetration. Two types of WTGU: Doubly Fed (DFIG) and Squirrel Cage (SCIG) Induction Generators are simulated and connected to grid with single circuit transmission line. The paper summarizes analytical investigations carried out on the impedance seen by distance relays by varying fault resistances...
High impedance fault (HIF) exposes great hazard for personal safety and property security. High impedance fault (HIF) in MV distribution with restricted fault current cannot be detected and cleared by conventional over current relays. In this paper, an integrated scheme utilizing different features of HIF is presented. Various documented field data has been investigated and summarized to get the most...
Distance relays used for transmission line protection can mal-operate on power swing. This paper presents protection schemes for out of step detection based on synchronized phasor measurement. Voltages and currents at both the ends of a transmission line are used to derive the parameters required for designing these schemes. The proposed schemes can distinguish stable and unstable power swing and...
In the last two decades there has been a continuous increase in the amount of Distributed Generation (DG) connected to the power network. This has resulted in a number of technical challenges for network protection including: sympathetic tripping of DG interface protection; blinding of feeder over-current (OC) protection; and deterioration of feeder OC protection grading. While the available literature...
This paper presents a new impedance based fault location method in the case of phase to phase and three phase faults. This method utilized the measured impedance by distance relay and super imposed current factor, which is the ratio of post-fault current to super imposed current, to discriminate the fault position on the line. This method is robust against the fault resistance. The presented method...
The present transmission systems are rapidly changing principally due to an increasing demand for better utilisation of existing lines resulting in lower transient stability limits, and also due to an increase in the complexity of the networks with small-scale distributed generation being connected into the existing networks. The current protection/fault location techniques are not conducive to such...
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