Areva MiCOM P441, Technical Manual

Page: 52 / 636

P44x/EN AD/E44 Update Documentation
Page 34/82
MiCOM P441, P442 & P444
Outputs for stable swing :
DDB N°351 : The first stable swing cycle has been detected (Zlocus in/out with the same R
sign) & the « Stable Swing start » picks-up
DDBN°353 : The number of cycles settable by S1 has been reached & Stable Swing is now
confirmed
DDBN°269 : Power Swing is detected (3 single phase loop inside the quad & crossing the
∆
R band in more than 5ms in a 50hz network)
Remark: Out-of-step tripping systems should be applied at proper network
locations to detect Out of step conditions and separate the network at
pre-selected locations only in order to create system islands with
balanced generation and load demand that will remain in
synchronism.
2.17 Directional and non-directional earth fault protection
Three elements of earth fault protection are available, as follows:
•
IN> element - Channel aided directional earth fault protection;
•
IN>1 element - Directional or non-directional protection, definite time (DT)
or IDMT time-delayed.
•
IN>2 element - Directional or non-directional, DT delayed.
•
IN>3 element - Directional or non-directional, DT delayed.
•
IN>4 element - Directional or non-directional, DT delayed.
The IN>1,IN>2 ,IN>3 and IN>4 backup elements always trip three pole, and have an optional
timer hold facility on reset, as per the phase fault elements. (The IN> element can be
selected to trip single and/or three pole).
These current thresholds are activated as an exclusive choice with Zero sequence
Power Protection.