Line Transfer Trip Criteria
Line Transfer Trip Criteria
(OP)
Fellow Power Folks,
I've been tasked with evaluating the need for Line Transfer Trip schemes (primary is DCB) on a handful of 115, 230, and 500kV Transmission Lines.
Our criteria currently states that it should be applied only on transmission lines where "infeed or impedance limit fault current contributions to values below relay setpoints under network conditions" or where sequential tripping is not acceptable.
This criteria seemed to work well in the age of EM relaying but doesn't hold up well with newer, more flexible digital relaying (as they can be set much more sensitively).
Does anyone have any thoughts/tips on developing an easier to apply/less subjective criteria?
I've read several papers/threads/etc discussing the "strength" of the source but mostly in reference to Generation transfer tripping.
Any help is greatly appreciated.
I've been tasked with evaluating the need for Line Transfer Trip schemes (primary is DCB) on a handful of 115, 230, and 500kV Transmission Lines.
Our criteria currently states that it should be applied only on transmission lines where "infeed or impedance limit fault current contributions to values below relay setpoints under network conditions" or where sequential tripping is not acceptable.
This criteria seemed to work well in the age of EM relaying but doesn't hold up well with newer, more flexible digital relaying (as they can be set much more sensitively).
Does anyone have any thoughts/tips on developing an easier to apply/less subjective criteria?
I've read several papers/threads/etc discussing the "strength" of the source but mostly in reference to Generation transfer tripping.
Any help is greatly appreciated.






RE: Line Transfer Trip Criteria
RE: Line Transfer Trip Criteria
Nowadays with digital relaying TT is part of relay.
So you do not need to make this discrimination: the price already include TT.
RE: Line Transfer Trip Criteria
Of course, there is still the minor cost of installing the communication system to transmit the transfer trip between substations...
RE: Line Transfer Trip Criteria
RE: Line Transfer Trip Criteria
http://www.selinc.com/sel-311l/
RE: Line Transfer Trip Criteria
RE: Line Transfer Trip Criteria
For high speed transfer tripping, the 311L's with F.O. communications is the way to go.