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This paper presents a new approach for locating short-circuit faults on untransposed transmission lines. Various fault-location algorithms have been proposed previously for transposed lines, which may not always be the case in practice. Existing methods usually require measurements recorded from one or two terminals of the faulted line, which may not be always available. To complement existing methods, this paper proposes a novel, general fault-location method for untransposed lines using sparse wide-area measurements, which is also applicable to transposed lines. Phasor measurement units are utilized to obtain the sparse wide-area synchronized measurements, which may be captured from buses far away from the faulted line. This method fully considers inherent unbalances of untransposed lines, and fully models shunt capacitances of lines based on a distributed parameter line model. Optimal estimation theory is exploited to make the most of available measurements for enhanced estimation. The method is able to locate faults on single-circuit and double-circuit line configurations, and is immune to fault resistances. Another feature of this method is that it does not require the fault type to be known. Extensive simulation studies using the Electromagnetic Transients Program have been performed, and quite accurate results have been achieved. [ABSTRACT FROM PUBLISHER]

This paper primarily addresses the subject of reducing outages or reducing the outage duration, auto-restoration applications for transmission substations, (where “transmission” is defined as 69 kV and higher), and the subject of proactively preventing outages. This paper is a summary of the report of K3-WG for transmission systems. The contribution of this paper includes the presentation of the state-of-the-art, practical techniques and measures for preventing and reducing outages in transmission substations which, if properly adopted, can significantly improve transmission system reliability. [ABSTRACT FROM AUTHOR]

A new fault-location algorithm for series-compensated double-circuit transmission lines utilizing two-terminal unsynchronized voltage and current measurements is presented in this paper. The mutual coupling between the parallel lines in the zero-sequence network is fully considered. The distributed parameter line model is adopted to fully take into account the shunt capacitance of the line. By formulating voltages and currents at the fault point in terms of the unknown fault location, boundary conditions under different fault types are used to derive the fault location. Two subroutines assuming the fault occurs on the left or right side of the series compensator are developed and the principle to identify the correct fault-location estimate is described. Matlab SimPowerSystems is employed to generate cases under diverse fault conditions for validating the proposed fault-ocation algorithm. Evaluation studies have shown that the proposed algorithm has achieved quite accurate results. [ABSTRACT FROM PUBLISHER]

This paper presents a new approach for locating short-circuit faults on a double-circuit transmission line. Various algorithms have been proposed previously that usually require measurements recorded from one or two buses of the faulted line. However, such measurements may not always be available in some scenarios, rendering inapplicability of existing methods. To complement existing methods, this paper proposes a novel, general fault-location method by harnessing voltage measurements at one or more buses, which may not be taken from the faulted line. The bus impedance matrix of each sequence network with the addition of a fictitious bus at the fault point can be derived as a function of the fault location. The fault location can then be obtained based on the bus impedance matrix and voltage measurements. The distributed parameter line model is utilized. The network data are assumed to be available so that the bus impedance matrix can be constructed. When multiple voltage measurements are available, an optimal estimator capable of identifying bad measurement data is also proposed for enhanced fault location. Since field data are not available at this time, simulated data are utilized for evaluation studies, and quite accurate results have been achieved. [ABSTRACT FROM PUBLISHER]

Various methods have been proposed in the past for locating faults on distribution systems, which generally entail iterative procedures. This paper presents novel fault-location algorithms for overhead distribution systems that provide a unified solution that eliminates or reduces iterative procedures applicable to all types of faults. Two types of methods, respectively, for nonradial systems and radial systems have been proposed by utilizing voltage and current measurements at the local substation. The proposed methods are based on the bus impedance matrix, through which the substation voltage and current quantities can be expressed as a function of the fault location and fault resistance, a solution to which yields the fault location. The methods are developed in phase domain and, consequently, are naturally applicable to unbalanced systems. The assumptions made are that the distribution network parameters and topology are known so that the bus impedance matrix can be developed. Simulation studies have demonstrated that both types of methods are accurate and quite robust to load variations and measurement errors. [ABSTRACT FROM AUTHOR]