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Line Phase Comparison Relay vs Line Differntial Relay
6

Line Phase Comparison Relay vs Line Differntial Relay

Line Phase Comparison Relay vs Line Differntial Relay

(OP)
Dear All.
What are advantages and disadvanteges of both type of protective relays.
Best Regards.
Slva

RE: Line Phase Comparison Relay vs Line Differntial Relay

Diff relays - needs longer control cables or some other circutary for current coparision purpose but are very highly accurate and reliable.

Distance Relays - Economical but not as accurate as differential relays.  With new technology numerical relays algorithms, they are faily reliable.

NC   

RE: Line Phase Comparison Relay vs Line Differntial Relay

(OP)
NCTHAI.
Thanks a lot for your reply.
Distance vs Differintial is not new for me.
My problem is some new type of protective relay ( for me, of course) line phase comparison relay.
According to manuals it's more or less diff protection, but base on another prinicpal, operated via PLC. ( power line carrier).
Something like to L60 vs L90 of GE, or some same types of ABB or Areva.
What is this, what is advantages, what is expirience.
Best Regards.
Slava
 

RE: Line Phase Comparison Relay vs Line Differntial Relay

(OP)
Guys!!!! Someone!!!
line phase comparison relay
What is this? It's work?

RE: Line Phase Comparison Relay vs Line Differntial Relay

http://selinc.biz/techpprs/6140.pdf

http://www.selinc.com/sel-311l.htm

Slava,

Maybe this will help.  I think they are basically differential relays using a comm channel to provide current data to the relay on the other end of the line.  I know that Bonneville Power has used some RFL units, but I never got too involved with any applications.  



 

RE: Line Phase Comparison Relay vs Line Differntial Relay

(OP)
Dear NCTHAI, Dave and Stevenal.
Thanks a lot for your reply.
As I understood, isn't standard application in utilities.
Best Regards.
Slava

RE: Line Phase Comparison Relay vs Line Differntial Relay

slavaq, according to me stevenal's explanation although very short is most correct. As per my knowledge phase comparison principle is used when communication channel with less bandwidth is available. Hence it has been used before, but now with relatively cheap OPGW's it is not a problem to ensure enough data speed to exchange full numerical information and line differential protections are more used nowadays.  

------------------------
It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
 

RE: Line Phase Comparison Relay vs Line Differntial Relay

(OP)
Good Morning.
Lz5pl and Zazmat thanks a lot to you too.
Lz5pl, I agree with you, you know what is DFZ and I try understand for what new type of relays with this algorthm.
Zazmat... no word.
Best Regards.
Slava

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