Can Relays be used to protect an alternator against one phase open circuits?
The relay then closes its contacts to disconnect the alternator from the system. Merz-price circulating-current system protects against phase-to-ground and phase-to-phase faults. … Advantage may be taken of this necessity to protect inter-turn faults on the same winding.
Which relay is used in protection of alternator against unbalanced loading?
Hence the relay operation under magnetizing inrush current can be prevented. Unbalanced loading of the stator winding produces negative sequence currents in it. This gives rise to additional heating of the stator winding. A negative sequence relay is used to sense this problem and hence the alternator is protected.
What are main protection used for alternator?
01. Stator winding fault. It is the most severe fault and considered most important for alternator protection. This vital protection of alternator stator is Differential circulating current scheme or Mertz price differential current protection scheme of alternator is discussed in a separate post.
Which relay is used in transformer?
Relays for Transformer Protection
|SL||Voltage Ratio and Capacity of Transformer||Common Relays|
|9||400/220KV 315MVA||Differential Relay Overflux Relay Buchholz Relay OLTC Buchholz Relay PRV Relay OT Trip Relay WT Trip Relay Over Load (Alarm) Relay|
What type of relay is suitable for radial feeders?
In radial feeder, the power flows in one direction only, which is from source to load. This type of feeders can easily be protected by using either definite time relays or inverse time relays.
Which abnormality is possible in alternator?
Alternators need to be protected not only from short circuits but also from abnormal operating conditions such as overexcitation, overvoltage, underexcitation, loss of field, unbalanced currents, loss of prime mover and abnormal frequency conditions.