Transformer Impedance Correction Tables Dialog

Concept Link IconSee Also

 

The Transformer Impedance Correction Tables dialog is used to view information about the transformer impedance correction tables. These tables are used on some LTC or phase shifting transformers to model the impedance of the transformer as a function of the off-nominal turns ratio or phase shift. The dialog has the following fields:

 

Transformer Impedance Correction Table Number

Number of the impedance correction table. Use the spin button immediately to the right of this field to step through the list of defined tables. If you have made changes to a particular table, you must click Save before moving to another correction table; otherwise, your changes will be lost.

Table Name

The name assigned to the table.

Table Entries

Used to insert/edit/delete the actual entries in the impedance correction table. In the first row, enter either an off-nominal turns ratio for an LTC transformer, or a phase shift in degrees for a phase shifting transformer. The entries in the first row must be entered in strictly ascending form. In the second row, enter the scale factor to apply to the transformer impedance. The transformer's nominal impedance is multiplied by the scale factor to obtain the actual value. To determine the appropriate scaling factor, interpolation will be used based on the current tap or phase angle. At least two columns must be used. Up to 100 points can be specified.

Right-click on the table to invoke its local menu, which allows you to delete and to insert columns. To insert a new column, click on the column before which you want to insert a new column and select Insert New Point from the local menu. To delete a column, position the cursor on the column you want to delete and select Delete Point.

Table is Used by the Following Transformers

Lists all the transformers in the case that use this impedance correction table. A single table may be used by any number of transformers. To associate a table with a transformer, use the Transformer AVR Dialog for LTC transformers or the Transformer Phase Shifting Dialog for phase shifters.