Overload Protection Relay

Overload Protection Relay: Overload Protection Relay - Continuous balanced overloading of a machine causes overheating in the stator winding. An obvious solution to this is the application of overcurrent relays;…

Continue Reading Overload Protection Relay

Rotor Protection

Rotor Protection: Rotor Protection - As pointed earlier rotor windings may be damaged by earth faults or open circuits. Figure (6.16) shows a modern method of rotor earth-fault detection. The…

Continue Reading Rotor Protection

Stator Protection

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…

Continue Reading Stator Protection

Generator Faults

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…

Continue Reading Generator Faults

Restricted Earth Fault Protection

Restricted Earth Fault Protection: This type of Restricted Earth Fault Protection is provided to detect earth-faults within the protected zone of the transformer. A CT is fitted in each connection…

Continue Reading Restricted Earth Fault Protection

Inrush Currents in Transformer

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…

Continue Reading Inrush Currents in Transformer

Percentage Biased Differential Relay

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…

Continue Reading Percentage Biased Differential Relay

Differential Protection of Transformers

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…

Continue Reading Differential Protection of Transformers