CIM Issues #6808
Determine if we can have BusbarSection and Junction on a single ConnectivityNode
IEC 61970-301
Description
Section 4.6.4.1 in the 301 jCleanCim template has, for CIM18, a new paragraph on BusbarSection and Junction classes. We've had a request to evaluate the following and update this section accordingly:
1. Can we have 2 BusbarSections on 1 ConnectivityNode?
2. Can we have BusbarSection & Junction on 1 ConnectivityNode.
We need to discuss if this is a UML restriction or should if it should be applied at the Profile level.
Proposed Solution
We recommend that the existing description in the BusbarSection class be changed to read:
"A conductor, or group of conductors, with negligible impedance, that serve to connect other conducting equipment within a single substation. The BusbarSection class is intended to represent physical parts of bus bars no matter how that bus bar is constructed.
Voltage measurements are typically obtained from voltage transformers that are connected to busbar sections. A bus bar section may have many physical terminals but for analysis is modelled with exactly one logical terminal."
For the Junction class update the description to:
"A point where one or more conducting equipments are connected with zero resistance.
The Junction class is intended to provide a place to associate additional information to a connectivity node which connects two or more equipment terminals. Examples include a tee-point or the connection point between two switches.
The Junction class is intended to provide a method to associate additional information, for instance Location, to a ConnectivityNode. Examples include a T-point or the connection point between two switches. Typically, BusbarSection objects and Junction objects are represented by different symbols on diagrams."
Decision
This was reviewed on 11-Jun-2024 at the Joint Hybrid Meeting in Tokyo and the proposed changes approved. This should be applied to CIM18v12
Release Notes
The description of BusbarSection was changed to "A conductor, or group of conductors, with negligible impedance, that serve to connect other conducting equipment within a single substation. The BusbarSection class is intended to represent physical parts of bus bars no matter how that bus bar is constructed.
Voltage measurements are typically obtained from voltage transformers that are connected to busbar sections. A bus bar section may have many physical terminals but for analysis is modelled with exactly one logical terminal."
The description of Junction was changed to "A point where one or more conducting equipments are connected with zero resistance.
The Junction class is intended to provide a place to associate additional information to a connectivity node which connects two or more equipment terminals. Examples include a tee-point or the connection point between two switches.
The Junction class is intended to provide a method to associate additional information, for instance Location, to a ConnectivityNode. Examples include a T-point or the connection point between two switches. Typically, BusbarSection objects and Junction objects are represented by different symbols on diagrams."