Principle of Distance Relaying

Principle of Distance Relaying: The Principle of Distance Relaying is governed by the ratio of voltage to current at the relay location and the operating time of the relay automatically…

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Directional Earth Fault Relay

Directional Earth Fault Relay: In the case of Directional Earth Fault Relay the angular relationship of residual current and residual voltage is independent of the faulted phase and is governed…

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Overcurrent Earth Fault Protection

Overcurrent Earth Fault Protection: Overcurrent Earth Fault Protection - Earth-fault protection can be provided with normal overcurrent relays, if the minimum earth-fault current is sufficient in magnitude. The magnitude of…

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Differential Relay Application

Differential Relay Application: The principle of operation depends on a simple circulating current principle where the difference of the currents of the two CTs flows through the relay under normal…

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Distance Relays Types

Distance Relays Types and their Applications: In applying relays to a transmission system it is necessary to state the relay characteristic in the same terms that the system conditions are…

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Single Phase Directional Relay

Single Phase Directional Relay: Single Phase Directional Relay - The general Eq. (4.8) suggests that for directional control the individual torques, viz. K |A|2 and K′ |B|2 should be eliminated. Considering a…

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Directional Relays

Directional Relays: Selective protection cannot be achieved with time graded overcurrent protection systems in ring or loop systems as well as in radial circuits with two end power supply. A…

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Relay Design and Construction

Relay Design and Construction: The Relay Design and Construction is normally divided into the following stages: Selection of the operating characteristics. Selection of proper construction. Design of the contact movement…

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