Multi-Section Lines Display

To show this display select Aggregations > Multi-Section Lines in the Model Explorer.

The Multi-Section Line Display lists the multi-section lines that exist in the case. The Multi-Section Line Display is used to functionally group a number of transmission lines together. They are usually used to model very long transmission lines that require the use of multiple individual transmission line information to be modeled accurately. Simulator then treats each multi-section line as a single device with regard to line status. That is, changing the status of one line in the record changes the status of the other lines in the record as well.

Each multi-section line record consists of the "from" bus, one or more "dummy" buses and the "to" bus. Each dummy bus must have only two lines connected to it, each of which are members of the multi-section line record. See Multi-Section Line Information for details.

The Multi-Section Line Display is a class of Case Information Display and therefore can be used in a manner consistent with all other case information displays. It has a local menu from which you can print, copy, and modify its information as well as view the information dialog of its multi-section line information. The local menu also affords the opportunity to insert new multi-section lines into the model or to delete existing ones when the application operates in the Edit Mode. Moreover, it enables you to invoke the Quick Power Flow List and Bus View Display for the line’s terminal buses. You can also sort the multi-section line information by clicking on the heading of the field by which you want to sort. Additionally, you can choose to restrict the information shown by the Multi-Section Line Display according to the constraints of the area/zone/owner filters.

While in Edit mode, the local menu allows three options that are specific to multi-section lines. The options are found under the Multi-Section Line records menu item.

Show Long Line Voltage Profile

For more information on this see the Long Line Voltage Profile topic.

Merge Sections

Select this option to eliminate the selected multi-section line record. If possible, the individual sections will be merged into a single line record between the from and to bus and the multi-section line record will be removed. If a multi-section line contains series capacitors or transformers, the multi-section line record will be retained.

Renumber Dummy Buses

This option allows renumbering/renaming the dummy buses that are part of a multi-section line by loading a file that has the new designations. The file containing the renumbering should be a text file in the following format:

frombus, tobus, circuit // this identifies the multi-section line

// frombus and tobus can either be bus numbers or name_nomkV combinations

dummybusnumber1, dummybusname1

dummybusnumber2, dummybusname2

frombus, tobus, circuit // this identifies another multi-section line

dummybusnumber1, dummybusname1

dummybusnumber2, dummybusname2

dummybusnumber3, dummybusname3

The file can either be space or comma delimited. A double slash can be used for a comment. A line with three entries is assumed to be a multi-section line and any two entry lines following that are assumed to be the dummy bus identifiers belonging to that multi-section line. Dummy buses are read for a multi-section line until another three entry line is found, meaning that a new multi-section line has been specified. Dummy buses are identified starting at the from bus of the multi-section line going to the to bus and that is the way that they should be entered in the file. If a multi-section line matching the given identifiers cannot be found, all dummy buses after that multi-section line record are ignored until a new multi-section line specification is found. If an incorrect number of dummy buses is entered for a multi-section line, none of the dummy buses will be updated. If the a dummy bus number is specified that matches an existing bus that is not another dummy bus, no changes will be made for that dummy bus. If a dummy bus number is specified that matches an existing bus that is another dummy bus, the other dummy bus will be assigned to a new bus number and the current dummy bus will be assigned to the number specified in the file.

Dummy buses can also be renumbered using the BUSRENUMBER SUBDATA section for a multi-section line in an aux file. The format of the SUBDATA section is the same as the file format given above for renumbering the individual bus numbers and the same rules apply. The benefit is that a separate text file does not need to be maintained with the renumbering. Dummy bus renumbering can only be done while in Edit mode. An aux file with the BUSRENUMBER SUBDATA section can be saved based on the existing dummy bus numbers using the SaveData script command or an Aux Export Format Description and specifying the SUBDATA section. Example SUBDATA sections for dummy bus renumbering are shown below:

DATA (MULTISECTIONLINE, [BusNum, BusNum:1, LineCircuit])

{

1 2 "1"

3 "BUS 3"

4 "BUS 4"

5 "BUS 5"

</SUBDATA>

22 33 "1"

14 "BUS 14"

15 "BUS 15"

</SUBDATA>

}

NOTE: When using the tool to renumber multi-section line dummy buses, either through the GUI or script, a new bus that does not exist no longer needs to have a bus name specified. By default the bus name will be the same as the bus number.

The display contains the following fields by default:

NumberFrom, NameFrom

Number and name of the multi-section lines from bus. Right-clicking on one of these fields invokes the display’s local menu from which you can select either Quick Power Flow List or Bus View Display to find more information about the from bus.

NumberTo, NameTo

Number and name of the multi-section lines to bus. Right-clicking on one of these fields invokes the display’s local menu from which you can select either Quick Power Flow List or Bus View Display to find more information about the to bus.

Circuit

Two-character circuit identifier for the multi-section line.

Sections

Number of individual lines within the multi-section line record.

Allow Mixed Status

This value defaults to NO and means that all branches in the multi-section line must have the same status. Setting this value to YES essentially means that the multi-section line is disabled so that opening/closing a branch in the multi-section line will no longer automatically open or close the other lines in the record.

Status

Current status of the record. Note, the status is Closed only if all the lines in the record are closed, and is Open only if all the lines in the record are open. Otherwise the status is Mixed.