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This paper describes briefly the ideal characteristics required for tripping for faults within the first zone of a distance relay adapted to the protection of a transmission line. The quadrilateral characteristic on an R-X diagram, which is the ideal characteristic, is obtained using a new hybrid comparison technique. This technique possesses the flexibility of conforming to any desired characteristic by a simple change in the selection of current inputs. The relays are described in their block schematic form.
In this paper the first zone distance relay is considered and the desirable shapes of its characteristics are discussed. A new hybrid comparison technique is used to obtain these desirable characteristics. The comparator models are described in their block schematic form. [ABSTRACT FROM AUTHOR]

This paper describes a new scheme for the protection of short transmission lines equipped with pilot wires. The relay scheme described employs semiconductor devices and works on impedance measurement. The effect of the complex nature of relaying current distribution factor and attenuation and phase shift of the relayed signal are taken into consideration in the analysis. The expression for power swing is developed and swing loci are plotted. Finally the protection characteristics to cover the internal faults are suggested and two schematic arrangements to realize the necessary characteristics are described. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of pulse circuits composed of a tunnel diode and a transmission line. The method employed, analysis in the v-i plane, is applied to the self-oscillation mode as well as to that of the one-shot mode. Effects of load and source (bias) impedance, linear and non-linear, are investigated. The analysis of non-linear biasing leads to configurations which present an improved triggering ability, shorter recovery time and less sensitivity to bias voltage variations. [ABSTRACT FROM AUTHOR]

This paper reports a comprehensive general analysis of sine comparators for distance protection of transmission lines. A mathematical basis is developed for realizing rectilinear characteristics and a graphical construction is presented to derive the necessary input signals for the sine comparators for obtaining a variety of pick-up characteristics on the impedance plane. A new criterion in multi-input sine comparators (sequence comparators) for the discrimination of faulty and healthy conditions of a protected transmission line section is established and a comparator model in schematic form is presented to realize the popular quadrilateral polar characteristics based on the new criterion. [ABSTRACT FROM AUTHOR]

Discretizing of fields is important in analogue simulation because it permits the construction of analogue models using lumped electrical elements, which are easier to design, manipulate and specify with high accuracy and precision. Such a process Of lumping in turn introduces an error in the propagation characteristics of the analogue model simulating the prototype. In this paper an attempt has been made to evaluate the error in the propagation characteristics of the lumped analogue model of a tidal channel. [ABSTRACT FROM AUTHOR]