Changing Line Properties

One type of branch in PSS/ADEPT is a line or cable that connects between two existing nodes.

To change the properties for a line:

1. Double-click on the line to select it and display the Line Property sheet, or, to select a line or group of lines, right-click, and choose Properties to display the Line Property sheet (Figure 3-26).

Figure 3-26. Line Property Sheet: Main Tab

2. Click the Main tab and select/enter the properties for a line or cable:

Name: Each item in the PSS/ADEPT network must have a unique name identifier. The line name has no relation to the FROM and TO nodes identified in the upper right of the Line Property sheet. The actual FROM and TO nodes provide network connectivity information and may not be modified.

Phasing: The phasing value indicates which phase conductors are present in the net-work model. In PSS/ADEPT, the available phasing values are specified using any com-bination of the three characters A, B, and C (e.g., ABC, AB, BC, CA, A, B, and C). You must select one of the phasing values from the list; you cannot enter your own values.

If XYZ phasing was specified in a PSS/U raw data file, PSS/ADEPT will convert

Users Manual Editing Branches

Line Length: The line length is the actual length of the branch. It is important that the line length is consistent with the impedance units. For example, if the line length is given in miles, then the impedance per unit length for the line must be specified in ohms per mile. This is important because line length is used to calculate the total line impedance.

Construction Type: Construction type is a 1- to 10-character alphanumeric identifier that refers to a construction type defined in the Construction Dictionary. You may select one of the construction types available in the Construction Dictionary, or you may enter your own (user-defined) unique construction type.

If you select a construction type from the list box, the impedance values defined with that type in the Construction Dictionary will be displayed in the Impedance area of the Line Property sheet; the values will not be editable. If you enter your own construction type, you must enter the impedance values associated with the line in the Impedance section of the Line Property sheet. PSS/ADEPT will save user-defined construction types and their associated impedances to the PSS/U raw data file (*.dat) and/or the native PSS/ADEPT native binary file (*.adp). User-defined line types are not saved to the construction dictionary.

Impedance: Both positive- and zero-sequence resistance and reactance must be specified in ohm per unit length. The positive-sequence and zero-sequence charging admittance must be entered in micro-Siemens per unit length. Unit length is user defined, and must coincide with the unit length used to specify the line/cable length.

You will not be able to edit these fields if you selected a construction type from the Con-struction Dictionary. If you created your own conCon-struction type, you must enter the impedance and admittance values; if you don’t enter any values, PSS/ADEPT will default to the displayed values.

Ratings: The line rating limits (amps) are used to determine whether a line is over-loaded. You may specify up to four rating limits either obtained directly from the Con-struction Dictionary or when a user-defined conCon-struction type is indicated, your own rating limits.

3. To display the line on the diagram, click once in the Visible check box to place a check mark there.

4. To indicate that the selected line is in service, click the In service check box, which is the default setting. If In service is not checked, the line/cable is out of service and is disconnected at both ends.

5. To display results for this line on the diagram, click once in the Results check box to place a check mark there.

6. To add the selected line to an existing group(s), click the Groups button and click the box that precedes the group name you want. Click the OK button to accept the assignment.

7. Click the OK button to accept your changes to the line properties.

To change the harmonic properties for a line (visible if you are licensed for the harmonics module):

1. Click the Harmonics tab to modify the harmonic properties of a line (Figure 3-27).

Figure 3-27. Line Property Sheet: Harmonics Tab

Name: The name of the line. This property is for information only and is not editable.

Click the Main tab to modify this item.

FROM node: The name of the FROM node to which this line is connected. This prop-erty is for information only and is not editable.

TO node: The name of the TO node to which this line is connected. This property is for information only and is not editable.

Type: Select the type of line representation from the drop-down list.

• IEEE Line – Represents an IEEE line. The modeling of an IEEE Line is described in Chapter 8, Section 8.9.5.

• IEEE Cable – Represents an IEEE cable. The modeling of an IEEE Line is described in Chapter 8, Section 8.9.5.

• Custom – Represents a user-defined line model for harmonics. Selection of this item will allow you to define the impedance exponents.

Users Manual Editing Branches

For custom types, enter the requested values for the following:

• Positive sequence resistance

• Positive sequence reactance

• Positive sequence susceptance

• Zero sequence resistance

• Zero sequence reactance

• Zero sequence susceptance

To change the reliability properties for a line (visible only if you are licensed for the DRA module):

1. Click the DRA tab to modify the reliability properties of a line (Figure 3-28).

2. Refer to Chapter 9, Section 9.4.2 for further instructions.

Figure 3-28. Line Property Sheet: DRA Tab