ABB Relion 670 series, Technical Reference Manual

Page: 95 / 1232

• Coarse message is sent every minute and comprises complete date and time, that
is, year, month, day, hours, minutes, seconds and milliseconds.
• Fine message is sent every second and comprises only seconds and milliseconds.
The SLM module is located on the AD conversion Module (ADM).
Synchronization via Built-in-GPS
The built in GPS clock modules receives and decodes time information from the global
positioning system. The modules are located on the GPS time synchronization Module
(GTM).
Synchronization via binary input
The IED accepts minute pulses to a binary input. These minute pulses can be generated
from, for example station master clock. If the station master clock is not synchronized
from a world wide source, time will be a relative time valid for the substation. Both
positive and negative edge on the signal can be accepted. This signal is also considered
as a fine time synchronization signal.
The minute pulse is connected to any channel on any Binary Input Module in the IED.
The electrical characteristic is thereby the same as for any other binary input.
If the objective of synchronization is to achieve a relative time within the substation
and if no station master clock with minute pulse output is available, a simple minute
pulse generator can be designed and used for synchronization of the IEDs. The minute
pulse generator can be created using the logical elements and timers available in the IED.
The definition of a minute pulse is that it occurs one minute after the last pulse. As
only the flanks are detected, the flank of the minute pulse shall occur one minute after
the last flank.
Binary minute pulses are checked with reference to frequency.
Pulse data:
• Period time (a) should be 60 seconds.
• Pulse length (b):
•
Minimum pulse length should be >50 ms.
• Maximum pulse length is optional.
• Magnitude (c) - please refer to section "Binary input module (BIM)" .
Deviations in the period time larger than 50 ms will cause TSYNCERR.
1MRK505222-UUS C
Section 4
Basic IED functions
89
Technical reference manual