ABB Relion 670 Series Application Manual page 98

Section 6
Appendix
Line differential protection IED with echo synchronization (no GPS clock)
• Both channels to have the same route with maximum asymmetry of 0.2–0.5 ms depending
on the set sensitivity of the line differential protection function
• Fixed asymmetry can be compensated for by setting the
PST
Line differential protection IED with GPS synchronization (GPS clock)
• Independent of asymmetry
92
© Copyright 2017 ABB. All rights reserved
1MRK 505 382-UEN E
AsymDelay on the local HMI or via
Communication set-up, 670/650 series
Application Guide