Static Amplitude Comparator: If the two input signals are S1 and S2 the amplitude comparator gives positive (yes) output only if S2/S1 ≤ K (Fig. (11.1)), S1 is the operating quantity…
Sampling Circuits: Sampling Circuits is one which allows a comparison of instantaneous values derived at different instants of time, thereby dispensing with the need to phase shift and mix signals…
Classification of Relay Testing: Classification of Relay Testing are usually conducted to demonstrate that: the relay will operate correctly to clear a fault; and the relay will remain inoperative on…
Phase Comparison Carrier Protection: The phase comparison pilot-relaying operates on the principle of comparing the phase position of the currents at the two ends of the protected section. The Phase…
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…
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…
Types of Electromagnetic Relays: There are two principal Types of Electromagnetic Relays: Attracted armature type; and Induction type. (a) Attracted Armature Type: This includes plunger, hinged armature, balanced beam and…
Derivation of Single Phase Quantity from Three Phase System: It will be seen later that auxiliary channels or pilot wires are used to transmit information from one end of the…