What is distance protection relay? where & why we use this
relay?
Answer Posted / singa
distance protection relays are used in transmission lines
in order to have the proper selectivity.
If a simple directional or non directional overcurrent
relays are used, then for a fault at remote SS, will cause
tripping if grading is not proper.
In addition, overcurrent relays settings are deponds on
SIR. Whereas distance protection relays are not deponds on
SIR but on the line impedence value.
Exact selectivity can be done by providing the different
zones viz, Zone-1,2,3,4
zone-1 will be instantaneous trip covers 80% of the line
where as zone-2 / 3 will covers some protion of adjacent
lines and trip after the time delay of say 200mS and 400mS
respectively.
Simply saying distance relays are under impedence relays
with directional feature.
| Is This Answer Correct ? | 11 Yes | 3 No |
Post New Answer View All Answers
Define ohm’s law for a.c (alternating current)?
What is the fault or needs to be done when frequency in ac drives is not changing?
is there any device that works properly accept relay, it may be fuse but if i want fuse of 33kv 300 amp it is avaliable, pls give me details
Whar is the KvA rating of 33Kv substation & actual kv rating of power generaating station.
How to select a transformer group to connect a 0,433 KV generation with 33 KV grid in bi directional flow of current
what is the difference between fault current ant short circuit current?
we have a rewind motor of 2Hp,2800Rpm, 220Volt AC. how can we choose the running capacitor for this motor, any formula for that?
Difference between field rheostat and armature rheostat.
at what basis/standard we have to arrive the current density of aluminium/ copper in busbar?
how can we calculate the ampacity of the electrical wire/cable. and what are the factors must be considered. pls. elaborate.
how to failure indution motor insulation & how to improve heat in motor insulation
in ACB breaker requireding 3200Amps. buscoupler getting OFF mode and again it reset and getting normal position give me a required answer?
Why need 3phase machine double earthing?
i want to learn control schedule for 11kv panel? can any one send the detailed control schedule?
What are the advantages of the three-phase motor over single phase motor?