This FAQ discusses the protection "Start" signal that is provided by Sepam through IEC61850 communication for all logical nodes corresponding to a protection function. For example, a user might wish to trigger an event or alarm when the pick-up for a specific protection function, such as Phase Overcurrent, or Earth Fault, has been raised.
By default, all of the logical nodes for protection functions on Sepam provide the .Str status information. One example, for the ANSI 50/51 function, is shown in the image below which is taken from the Sepam IEC61850 manual:
The screenshot below shows how the same "Start" parameter for Unit #1 of the ANSI 50/51 protection function can be added to a Dataset in the CET850 software:
It should be noted that although this "Start" signal is provided by Sepam for all the protection functions, it is not specific to each protection function. In other words, if the pick-up threshold for any one of the protection functions in the relay has been exceeded, then the "Start" signal will become true for all of the logical nodes for protection functions. This limitation is due to the fact that the "Start" signal is tied to the global pick-up signal maintained internally by Sepam, rather than the individual pick-up signal for each protection function. It is the same information that is given by the "PUP" signal in COMTRADE waveforms recorded by Sepam.
In some cases, a user may wish to define a signal for IEC61850 communication that reflects only the pick-up status for a specific protection function unit (e.g., Unit #1 of the 50/51 function). This can be realized on Sepam by using the SFT2885 software to build a simple ladder diagram.
As shown in the image below, the Logipam software gives the user access to all the internal signals that are updated by Sepam, including the "instantaneous output" (or pick-up) for each individual protection function. For this example, we show how to create a customized signal in IEC61850 that is published using a Remote Indication bit. The Remote Indication bit can then be accessed in the IEC61850 database of the device, and it can be added to Datasets which would allow it to be sent as a GOOSE message, for example.
Once the Logipam program has been loaded to the Sepam, the next step is to find the way to access our customized Remote Indication bit in the CET850 software, which is the main IEC61850 configuration software for Sepam relays. As shown in the screen shots below, the "TS33" bit used in our example can be accessed through the LGP_GGIO1 Logical Node. For example, to obtain the status of TS33 as a single status bit, we would use the following address:
LGP_GGIO1.Ind1.stVal
As shown in the screen shot below from the CET850 software, this data point can now be added to a Dataset in the CET850 software, which would allow the user to send it as a GOOSE message, or to trigger Event Reports using the status of this signal.
To summarize, this FAQ has described the usage of the "Start" signal that is provided by default in Sepam Series 80 ICD file templates. We have also seen how a customized Remote Indication signal could be defined using the SFT2885 software in order to create a pick-up signal specific to a protection function of the user's choice. This FAQ document also has a sample SFT2885 file attached.