Star Winding and Delta Winding: Star Winding and Delta Winding - The magnitude of earth-fault current for a given fault position within a winding depends upon the winding connections and the method of neutral earthing.…
Inrush Currents in Transformer: Magnetizing Inrush Currents in Transformer contain pronounced harmonics but the current during internal fault conditions is sinusoidal. Advantage is taken of this fact in the design of the relay. It was…
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 tap changing, a restraining winding…
Differential Protection of Transformers: Differential Protection of Transformers is the most important type of protection used for internal phase-to-phase and phase-to-earth faults and is generally applied to transformers having ratings of 5 MVA and above.…
Transformer Protection Types: Nature of Transformer Faults: Power transformers, being static, totally enclosed and oil immersed develop faults only rarely but the consequences of even a rare fault may be serious, unless the transformer is…
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 Comparison Carrier Protection of these…
Carrier Pilot Protection and Microwave Pilot Protection: The problem of providing economically an auxiliary channel by means of pilots for long lines directed attention to carrier techniques. In this case the power line itself is…
Pilot Wire Protection Relay: In this case the auxiliary Pilot Wire Protection Relay are provided to carry the information signals from one end to the other. Protective systems requiring the use of pilot wires on…
Application of 3 Phase System: In a Application of 3 Phase System, a wide variety of faults can occur, i.e. phase to phase, phase to earth, 2 phase to earth and 3 phase fault, various…
Selection of Distance Relay: The factors to be considered for the Selection of Distance Relay scheme can be enumerated as follows: Speed of operation. Measuring relay characteristics. Fault coverage. Economic considerations. 1. Speed of Operation:…