Loss of Excitation Protection: Two distinct effects of Loss of Excitation Protection are that the machine starts drawing magnetizing current of large magnitude from the system, and the slip frequency…
Stator Protection: Stator Protection - The type of stator faults likely to occur have been discussed already. The earth-fault current is usually limited by resistance in the neutral of the…
Generator Faults: Generator faults can be considered under the following heads. (a) Stator Faults: These include the following: Phase-to-earth faults. Phase-to-phase faults. Inter-turn faults. Most faults occur in the stator…
Percentage Biased Differential Relay: Percentage Biased Differential Relay - In order to avoid undesirable operation on heavy external faults due to CT errors and ratio change as a result of…
Power Swings in Power System Protection: The impedance measured or seen by a distance relay during normal load is shown in Fig. (5.29). Normally this would be outside the tripping…
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…
Important Questions of Protection of Alternators and Transformers: 1. Discuss the important faults on an alternator. 2. Explain with a neat diagram the application of Merz-Price circulating current principle for…
LED Seven Segment Display: The arrangement of a LED Seven Segment Display is shown in Fig. 20-6(a). The actual LED devices are very small, so, to enlarge the lighted surface,…