CIM Issues #6786
Add clarification that BaseVoltage.nominalVoltage is line-to-line
Description
For distribution modeling, there is ambiguity whether BaseVoltage.nominalVoltage is line-to-neutral or line-to-line.
Existing description: "The power system resource's base voltage. Shall be a positive value and not zero."
Proposed description: "The power system resource's base voltage, expressed on a line-to-line basis. Shall be a positive value and not zero."
Proposed Solution
For distribution modeling, there is ambiguity whether BaseVoltage.nominalVoltage is line-to-neutral or line-to-line.
Existing description: "The power system resource's base voltage. Shall be a positive value and not zero."
Proposed description: "The power system resource's base voltage, expressed on a line-to-line basis. Shall be a positive value and not zero."
Decision
05-Jun-2024 - Reviewed in weekly TF13 call:
After a thorough discussion TF13 has confirmed the following updates in CIM18:
Update the description to BaseVoltage.nominalVoltage:
"The power system resource's base voltage, expressed on a phase-to-phase (line-to-line) basis. Shall be a positive value and not zero."
From Electropedia.com both line-to-line and phase-to-phase are noted but that line-to-line is a regionalized term so we want to include both but to add the later parenthetically.
Update description on the BaseVoltage class to:
"Defines a system base voltage which is referenced. This may be different than the rated voltage."
Release Notes
- the description of BaseVoltage class was changed to "Defines a system base voltage which is referenced. This may be different than the rated voltage."
- the description to BaseVoltage.nominalVoltage was changed to "The power system resource's base voltage, expressed on a phase-to-phase (line-to-line) basis. Shall be a positive value and not zero."
Updated by Todd Viegut about 1 month ago
05-Jun-2024:
Part of today's discussion is that the BaseVoltage (being associated with VoltageLevel) is the operating voltage. It is not the same as the rated voltage. The nameplate is based on the rated voltage. Can not assume that the BaseVoltage is the basis for P.U.
Usually the rated voltage is used for determine P.U. This depends on which P.U.s and where we have them. Thus why we define everything as kV in the CIM as we intentionally avoid have anything in CIM in P.U. However, where/when we do have P.U. you must specify what the basis (rated voltage) is in order to calculate P.U.
In the new CGMES 3.0.0 guidance has been given to use the BaseVoltage on the ACLineSegment to determine P.U. (this was a recommendation for vendors in the IEC 61970-600 only for their internal processing...and NOT something explicitly in the standards).
We confirmed the following for the CGMES on this topics:
- In the CGMES 2.4.15 E10.1 specifies that the P.U. are based on BaseVoltage.
- In the CGMES 3.0.0 the P.U. values no longer exist and clause E10.1 has been removed.
NOTE: We can't dictate global business processes.
In the CIM17 452 we have one constraint (it makes sense here):
C:452:EQ:RegulatingControl.targetValue:tapChanger
In cases where RequlatingControl.mode is "voltage" and both
TapChanger.controlEnabled and RequlatingControl.enabled are "true",
o The RegulatingControl.targetValue in per unit value is calculated by
RegulatingControl.targetValue/BaseVoltage.nominalVoltage.
shall be within the regulating capability limits:
o The tap changer upper capability limit in per unit value is calculated by
1+RatioTapChanger.stepVoltageIncrement/100*(TapChanger.highStep
TapChanger.neutralStep).
o The tap changer lower capability limit in per unit value is calculated by 1
RatioTapChanger.stepVoltageIncrement/100*(TapChanger.neutralStep -
TapChanger.lowStep).
Updated by Chavdar Ivanov about 1 month ago
- Status changed from New to Open
- Base Release set to CIM18
- Solution to be Applied To set to CIM18v11
- Solution Version set to CIM18v11
- Solution Applied By set to Chavdar Ivanov
- Completion Date set to 06/05/2024
- Release Notes updated (diff)