This dialog box includes the following areas and tabs:
Figure 1: Zigzag Data Dialog Box
ID Name: Uniquely identifies the transformer. This ID name is sometimes referred to as the transformer name, and can be up to 12 characters long. The names default to TZ-1, TZ-2, TZ-3, and so on as you enter new transformers on the one-line diagram, but you can change those names later if needed.
From Bus: The bus from which the transformer connects, which must already exist on the one-line. For reference, the From Bus base kV is displayed next to the bus name.
Voltage Rating (kV): Transformer nameplate rated kV.
Impedance (Ohms): Transformer nameplate impedance in ohms. This is the impedance between each line terminal and neutral.
R: Transformer neutral ground resistance in ohms.
jX: Transformer neutral ground reactance in ohms.
Use the Harmonics tab to indicate whether this equipment item is introducing harmonics into your power system.
EasyPower offers two methods for calculating RH:
RH = RFund * H R-EXP
RH = RFund * (1+ECF*H2)/(1+ECF)
EasyPower defaults all skin effect correction to R-EXP and a value of 0.5.
R-EXP | %ECF | |
---|---|---|
Transformer |
0.5-1.0 |
1.0-3.0 |
Utility |
0.0-0.8 |
- |
Generator |
0.3-0.6 |
- |
Line/Cable |
0.5 |
- |
Reactor |
0.5-1.0 |
0.8-3.0 |
Motor |
0.2-0.4 |
- |
Use to set the fundamental amps. The options are as follows:
To use fundamental current calculated by power flow, select Calculated from Power Flow in the Summation Fundamental Voltage area of the Harmonics Options > Control dialog box.
This tab is read-only and appears only if you have imported data from an SKM Data Format file. See Importing an SKM Format File for more information.
See Comments for information.
See Hyperlinks for information.
Database Technical Reference |