What is the requirement for Unit handling

CGMES v3.0 does currently only support fixed unit for any given attributes. For active power this means Mega Watt (MW), this is not nature for distribution.

The first step would be if a given profile should support fixed unit or the possible to change.

Given that all exchange are fixed, should we a. keep the current (e.g. MW for ActivePower) b. move to new that is TSO and DSO friendly (e.g. kW for ActivePower) c. cut the use of multiplier (e.g. W for ActivePower)
Given that the profile can support multiple unit on the same attribute (e.g. a TSO can send in MW and DSO in kW) a. Should it only be a pre-defined list (e.g. only kW and MW - but not possible to use W) b. Fix the unit (e.g. W) - but allow to choose multiplier (e.g. use W (no multiple), kW, MW, TW etc)

In principle there could be some variable that we can use different unit (e.g. length meter, feet etc) but I think it is clear that there are no use cases in Power System for this.

What level of flexibility are required for DSO - DSO (including internal) and TSO-DSO?

Example for unit and multiplier handling:

    <cim:ACLineSegment rdf:ID="_9d58e5bb-834c-4faa-928c-7da0bb1497d9">
        <cim:IdentifiedObject.description>400 Volt Telemarkstien 2 ACLineSegment 1</cim:IdentifiedObject.description>
        <cim:IdentifiedObject.name>04 TELEMA 2 ACLS1</cim:IdentifiedObject.name>
        <cim:IdentifiedObject.aliasName>Telemarkstien 2</cim:IdentifiedObject.aliasName>
        <cim:Equipment.aggregate>false</cim:Equipment.aggregate>
        <cim:Equipment.networkAnalysisEnabled>true</cim:Equipment.networkAnalysisEnabled>
        <cim:Equipment.normallyInService>true</cim:Equipment.normallyInService>
        <cim:Conductor.length multiplier="none" unit="m">0.03125</cim:Conductor.length>
        <cim:ACLineSegment.b0ch multiplier="none" unit="ohm">0</cim:ACLineSegment.b0ch>
        <cim:ACLineSegment.bch> multiplier="none" unit="ohm"0</cim:ACLineSegment.bch>
        <cim:ACLineSegment.g0ch multiplier="none" unit="ohm">0</cim:ACLineSegment.g0ch>
        <cim:ACLineSegment.gch multiplier="none" unit="ohm">0</cim:ACLineSegment.gch>
        <cim:ACLineSegment.r0 multiplier="none" unit="ohm">0.0000125000005937181</cim:ACLineSegment.r0>
        <cim:ACLineSegment.r multiplier="none" unit="ohm">0.0000031250001484295353</cim:ACLineSegment.r>
        <cim:ACLineSegment.shortCircuitEndTemperature multiplier="none" unit="degC">0</cim:ACLineSegment.shortCircuitEndTemperature>
        <cim:ACLineSegment.x0 multiplier="none" unit="ohm">0.0000125000005937181</cim:ACLineSegment.x0>
        <cim:ACLineSegment.x multiplier="none" unit="ohm">0.0000031250001484295353</cim:ACLineSegment.x>
        <cim:PowerSystemResource.AssetDatasheet rdf:resource="#_d25f35ca-69fb-4c06-905b-67ec532e5f14"/>
        <cim:ConductingEquipment.BaseVoltage rdf:resource="#_9598e4a0-67e5-4ad7-879c-c85a1f63159c"/>
    </cim:ACLineSegment>

3lbits / CIM4NoUtility

What is the requirement for Unit handling #33