3.4.2 Time synchronization
3.4.2.1 Application
Use time synchronization to achieve a common time base for the IEDs in a protection
and control system. This makes it possible to compare events and disturbance data
between all IEDs in the system.
Time-tagging of internal events and disturbances are an excellent help when evaluating
faults. Without time synchronization, only the events within the IED can be compared
to one another. With time synchronization, events and disturbances within the entire
station, and even between line ends, can be compared at evaluation.
In the IED, the internal time can be synchronized from a number of sources:
• BIN (Binary Minute Pulse)
• GPS
• SNTP
• IRIG-B
• SPA
• LON
• PPS
Odut of these, LON and SPA contains two types of synchronization messages:
• Coarse time messages are sent every minute and contain complete date and time,
that is year, month, day, hour, minute, second and millisecond.
• Fine time messages are sent every second and comprise only seconds and
milliseconds.
The setting tells the IED which of these that shall be used to synchronize the IED.
It is possible to set a backup time-source for GPS signal, for instance SNTP. In this
case, when the GPS signal quality is bad, the IED will automatically choose SNTP as
the time-source. At a given point in time, only one time-source will be used.
3.4.2.2 Setting guidelines
System time
The time is set with years, month, day, hour, minute, second and millisecond.
Synchronization
The setting parameters for the real-time clock with external time synchronization
(TIME) are set via local HMI or PCM600.
1MRK504116-UUS C Section 3
IED application
75
Application manual
To Next Page
Loading...
