Add support for temperature dependent limits

[Sveino]

As part of Statnett change request to get support for dynamic line rating.

8.1 Calculating the OperationalLimits based on temperature
The Operational Limits calculated with the temperature-based method should be allocated to the same OperationalLimitSets that is exported in the EQ, that does not have an association to RateTemperature and is not linked to Auxiliary Equipment. The OperationalLimitSets' OperationalLimits is updated with the calculated value. Operational Limits could be any or several of the following types: VoltageLimit, CurrentLimit, ApparentPowerLimit and ActivePowerLimit. The OperationalLimits' OperationalLimitType could be of any of the LimitTypes specified in QoCDC 3.3.

8.2 Equipment (EQ) export
The EQ export should only contain the OperationalLimitSets without association to Rate Temperature, and without a link to Auxiliary Equipment. These should be the same OperationalLimitSets that is used by the Seasonal Limits method. It shall export all related OperationalLimits to these OperationalLimitSets.

8.3 Steady State Hypothesis (SSH) export
Add the possibility to enable/disable the inclusion of Operational Limits in the SSH. This is not a must requirement.
The SSH export file should include the update of the Operational Limits referring to the same OperationalLimit that is in the EQ. Therefore, the Operational Limits will be rdf:about. All the condition A, B and C limits shall be exported.

8.4 Operational Limits in an EQ-diff instance file
Add the possibility to enable/disable the creation and export of an EQ-diff instance file for the Operational Limits change, per MTU.
The Operational Limit EQ-diff instance export file shall remove (reverse differences) the values of the Operational Limits in the EQ export and replace them (forward differences) with the values that has been calculated based on the temperature-based method. All the condition A, B and C limits shall be exported.

8.5 File reference dependency
The file header depending on shall follow the instruction in Figure 6. If the EQ-diff instance file is produced, the header in the SSH "DependingOn" needs to point to the EQ-diff file rather than the EQ file.

Figure: File dependency

[tviegut]

@Sveino : I understand the general use case for dynamic line ratings and limits, etc. but maybe some additional clarity for the contexts for the exports described. As for the rational depicted in the file dependency diagram...that's clear.  Just a couple of questions if I may. Related to 8.3:

Add the possibility to enable/disable the inclusion of Operational Limits in the SSH. This is not a must requirement.
The SSH export file should include the update of the Operational Limits referring to the same OperationalLimit that is in the EQ. Therefore, the Operational Limits will be rdf:about. All the condition A, B and C limits shall be exported.

Is the context of the export described here. Is this SSH export (which here described includes updated limit sets account for the calculated dynamic line ratings) the output/results of analysis for a converged PF to be included in an IGM to be exchanged? That is my assumption but could you confirm (or is it to serve as input that take into account updates for the OperationalLimitSets? If so...is the rdf:about in this example expected to overwrite any values that may exist in an EQ that an SSH of this nature is merge with?)

For 8.2, we have in CGMES 3.0.0 EQ profile OperatoinalLimitSet per the standard. In understanding the context for what is described is that assuming an EQ that has had updates made to its base OperationalLimitSet-s that produce delta based on dynamic limit updates. Thus in turn you could have a difference model as described in 8.4 (?).

Thanks in advance for any confrimation.

[Sveino]

The challenge is that this is related to CGMES v2.4 that does not have OperationalLimit included as IEC 61970-456:2018 ED2 and CGMES v3.0. As we do not have anyway to describe the temperature limits in CIM we have made an extension. This is an extension that was suggested in CGMES v2.5 that was not approved but implemented by some of our vendors. ENTSO-E NC v2.2 has another way. The diagram is:

The Nordic44 EQ include this extended. In addition the RCC is requesting to get hourly changed to the OperationalLimit as a EQ-diff instead of SSH. The use case try to deal with both possibilities.