Time Synchronization - ABB REB670 Applications Manual

Section 18
Basic IED functions
18.16
18.16.1
478
Both hardware and software supervision is included and it is also possible to indicate
possible faults through a hardware contact on the power supply module and/or through the
software communication.
Internal events are generated by the built-in supervisory functions. The supervisory
functions supervise the status of the various modules in the IED and, in case of failure, a
corresponding event is generated. Similarly, when the failure is corrected, a
corresponding event is generated.
Apart from the built-in supervision of the various modules, events are also generated when
the status changes for the:
• built-in real time clock (in operation/out of order).
• external time synchronization (in operation/out of order).
Events are also generated:
• whenever any setting in the IED is changed.
The internal events are time tagged with a resolution of 1 ms and stored in a list. The list
can store up to 40 events. The list is based on the FIFO principle, that is, when it is full, the
oldest event is overwritten. The list contents cannot be modified, but the whole list can be
cleared using the Reset menu in the LHMI.
The list of internal events provides valuable information, which can be used during
commissioning and fault tracing.
The information can only be retrieved with the aid of PCM600 Event Monitoring Tool.
The PC can either be connected to the front port, or to the port at the back of the IED.

Time synchronization

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. If a global common source (i.e. GPS) is used in different substations
for the time synchronization, also comparisons and analysis between recordings made at
different locations can be easily performed and a more accurate view of the actual
sequence of events can be obtained.
Time-tagging of internal events and disturbances are an excellent help when evaluating
faults. Without time synchronization, only the events within one IED can be compared
1MRK 505 337-UUS -
Application manual