Area, BalancingAuthority, Zone, Substation and Owner Objects
There are several aggregation definitions which can group together objects in a particular manner. The treatment in the data structure for these is defined here.
Area, BalancingAuthority, and Zone objects
Area, BalancingAuthority and Zone objects have the same treatment in the data structure.
Defining Area, BalancingAuthority, Zone objects
Each Bus in the model must be assigned to exactly one Area, exactly one BalancingAuthority and exactly one Zone. Note that there does not need to be any relationship at all between Area, BalancingAuthority and Zone objects. Frequently a zone is modeled as a sub-region of an area, but this does not need to be true. In most situations this is the end of the input specification, however, the objects Gen, Load, and Shunt may also be assigned to an Area, BalancingAuthority or Zone that is different than the terminal bus.
Using Area, BalancingAuthority, and Zone objects in Filtering
How the Area and Zone definitions are interpreted will depend on where they are used. For example, when filtering devices Gen, Load, or Shunt objects then they will obey any area/BA/zone assigned to the particular object, or if none is assigned they will use the area/BA/zone designation with the terminal bus.
For devices that have multiple terminals though, such as a Branch or DCTranmissionLine, then the device will be considered inside the area, BA, or zone if any of its terminals is inside. Interfaces will be inside an area, BA, or zone if any of the InterfaceElement devices are inside it.
Using Area, BalancingAuthority, and Zone objects with regard to losses on Tie-lines
When looking at which Area, BalancingAuthority, or Zone object is assigned the losses on a tie-line between two of them, then the device connecting them will have a “MeteredEnd” specified. The losses will then be assigned to the non-metered end.
Substations
Each Bus in the model can be assigned to one substation. This is not a requirement, but an option. For the purposes of filtering, an object is considered to meet the substation filter if any of the terminal buses are in the substation.
Owner
Owners are a slight modification to the aggregation concept because for some devices (Gen, Branch, Shunt), the object can be partially owned by several different Owner objects. When used with filtering the device will be considered “inside” the Owner if any part of it is owned. When showing totals such as total generation MW or Mvar, then a pro-rated portion of the generation output will be shown.