The GOOSE frame is also not accepted if ConfRev deviates from the one in the
configuration. These error situations can be observed in the GSELPRT1 diagnostic
counters.
The default GOOSE input value is “0” for all the data types. The functionality is
analogous to physically wired galvanic Normally Open (NO) contacts where the
disconnected signal gives value “0” of FALSE to relay application. The application
must be designed to withstand the default value. This value is used when the
subscribed GOOSE data is not valid, or it is not received from the network and the peer
device is considered to be in a time-out state.
If a peer device sends the data including the quality attribute, the receiver device input
object is not updated according to the received status value if the data quality is bad,
questionable or blocked. The default value is also used in this case.
5.7 GOOSE supervision
5.7.1 Background sending
To ensure reliability and availability of the application, the GOOSE communication
must be supervised. Design the application so that it can handle communication
losses, for example, when a peer device is not available or there are communication
time-outs.
If there are no GOOSE-related data changes, the protection relay resends the last
GOOSE message with a heartbeat cycle to enable the receiver to detect
communication losses. The heartbeat cycle is defined by modifying the MaxTime
property on GOOSE control block.
Every GOOSE frame has a TAL field which shows how long the frame is valid until
the next heartbeat frame. Other devices may have their own TAL values.
Nevertheless, all the TAL values under 1000 ms are rounded up to 1000 ms on the
receiving side.
If no frames are received during 2xTAL, that is, if at least two consecutive frames are
lost, then the receiver considers the whole data set as invalid. The quality attribute for
the entire data set is set to "bad" and the values are set to their default values. This is
an important consideration when designing the application as the default values need
to be "fail-safe" values. For example, the protection relay should use an enabled signal
for interlocking and a blocking-type signal for protection.
5.7.2 Default value handling
The information is of point-to-point type which means that there is only one signal
connected to the function block input.
1MRS757809 C Section 5
GOOSE
REC615 and RER615 53
Engineering Guide
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