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…
Overcurrent Protection of Feeders: Overcurrent relays offer the cheapest and the simplest protection for lines. The maximum load currents must be known to determine whether the ratio of the minimum…
Types of Feeder Protection Relay: A composite transmission system may use one or more of the following types of Feeder Protection Relay. Overcurrent Protection: This is of two types: (i)…
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…
Directional Overcurrent Relays in Power Systems: Directional Overcurrent Relays in Power Systems - Relay connections must be made so that the currents and voltages applied to the relay during the…
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…
Time Current Relay Application: Time Current Relay Application - Overcurrent and earth fault protective gear can be made discriminative by grading the operating times of successive devices. The pickup currents…
Instantaneous Overcurrent Relays: If the relay operates instantly without any intentional time delay, this characteristic can generally be satisfied by a relay of the non-polarized attracted armature type. This relay…