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A transmission line distance relaying technique using an on-line trained neural network (NN) is developed. Results of numerical simulation and experimental studies show very good ace curacy and fast estimation of distance to fault for various faults under different operating conditions, high fault resistance, and it- mote-end feed. [ABSTRACT FROM AUTHOR]

A scheme for the protection of parallel transmission lines using wavelet transform (WT) has been implemented and results of experimental tests on a physical power system model are described. The relaying scheme depends on the three line voltages and the six line currents of the two parallel lines at each end. Fault detection, fault discrimination and calculation of the phasors of the measured signals are done using WT. The performance of the proposed scheme has been investigated by a number of online tests. The results show that all types of shortcircuit faults can be correctly identified in less than one cycle of the fundamental frequency. [ABSTRACT FROM AUTHOR]

A novel digital distance scheme has been implemented on a 32-bit digital signal processor board. The scheme is tested on a physical model of double circuit lines of equal impedance with a source at each end. Two relays instead of four are proposed for the two lines. Each relay is fed by three voltage and six current signals. The technique is based on the comparison of the measured impedance of the corresponding phases. Tests conducted on the physical model for various faults show that high fault resistance, current in-feed, balance-point location, out-of-step operation, and far-end faults arc solved. Moreover, 100% of the line is protected. [ABSTRACT FROM AUTHOR]

Wavelet transform (WT) has the ability to decompose signals into different frequency bands using multiresolution analysis (MRA). It can be utilized in detecting faults and to estimate the phasors of the voltage and current signals, which are essential for transmission line distance protection. A digital distance-protection scheme for transmission lines based on analyzing the measured voltage and current signals at the relay location using WT with MRA is presented in this paper. The scheme has been tested by both computer simulation and experimentally. The tests presented include solid ground faults, phase faults, high impedance and nonlinear ground faults, and line charging. [ABSTRACT FROM AUTHOR]

A new scheme to enhance the solution of the problems associated with parallel transmission line protection is presented in this paper. The scheme depends on the three line voltages and the six line currents of the two parallel lines at each end. Fault detection, fault discrimination, and calculation of the phasors of the measured signals are done by using wavelet transform (WT). By comparing the magnitudes of the estimated current phasors of the corresponding phases on both lines, internal faults on the parallel lines can be identified. Also, by calculating the distance element of the phases on which a disturbance is detected and having a very small current difference magnitude can enhance and strengthen the scheme. Studies show that all types of faults at different loading conditions can be correctly identified in less than one cycle of the fundamental frequency. [ABSTRACT FROM AUTHOR]

Discusses a study which showed the possible application of neural network technique to the single-ended fault location for power transmission lines. Highlights of the study. INSET: Closure to Discussion of 'Articial Neural Network Approach....