Hi All,
Can somebody give me any guidelines on what settings to use for rate of change of frequency? Would you normally do some simulations before choosing settings or just use a 'generic' recommended one.
Also, would you tend to use normal ROCOF or frequency supervised one?
Dear All,
In a substation we have protection CTs in one place and the circuit breakers in another. What I'm interested in is what can be the capacitance of the wire connecting both, or at least the distance between CTs and CB.
What I'm trying to understand is how much current (and for how long)...
Hi All,
Any ideas why to use undervoltage blocking for frequency functions (except the obvious one that below approx. 10% of Vnominal the accuracy may not be satisfactory)?
I heared some people wanting to set undervoltage blocking to 30% Vnom - are there any reasons to do that? Will these...
Hi All,
Can you tell me how do you connect Buchholz/SPR to trip CB - do you connect it directly to the CB or do you connect it via IED's binary inputs (or both - in parallel)?
By the way - is there a difference between Buchholz and SPR?
Regards,
Peter
Hi All,
Is there any 'magic equation' that allows to estimate the physical size of CT (i.e. length, width, height) based on the turns ratio, VA rating and type of core? How can I actually make sure that the CT will fit where I want to put it (in a cubical for example).
I mean protection CTs...
Hi All,
I'm interested in hearing your opinions on using distance relays on distribution networks - how common is it, do you use it mostly as primary or backup, what are the expectations as far as the operating time is concerned (is ~30ms acceptable for Zone1), are you trying to use it on...
