Secondary Fault Analysis

Note!

Secondary Fault Analysis must be run with the Interactive Apps option selected (from GUI Options dialog).  Otherwise, the application will not run, as the transformer, attachment and secondary line details are established interactively during execution.

 

Application Overview:

 

Secondary Fault Analysis allows user to choose a primary circuit component for connection to a distribution transformer and determines resulting currents due to secondary faults for selected transformer configuration.

 

Application Run / Results:

Results for Secondary Fault analysis are only viewable from the generated report, as there are no defined output variables available for display.  

 

Running the interactive Secondary Fault Analysis application opens the setup dialog, as described in the Secondary Fault Analysis Setup topic.  

After the setup parameters have been accepted, the application enters the interactive mode (i.e. with active mouse pointer finger) to select the component location where the distribution transformer will be attached.    

Once the component location has been selected (via single-left mouse click), the Distribution Transformer Connection dialog opens with a list of the possible transformer connections, as shown below:

  

From the available list, Select (i.e. Highlight) the distribution transformer connection desired for the selected location.  
 

Available Commands:

[Next] - accepts the selected transformer connection and opens the Transformer and Secondary Line Data dialog.

[Back] - returns application to the setup dialog, allowing user to modify setup or subsequently change location for transformer attachment.  

[Exit] - cancels execution of Secondary Fault Analysis and returns user to main drawing window.  

 

After the transformer connection has been accepted, the Transformer and Secondary Line Data dialog opens for user specification of additional transformer and secondary conductor properties, shown  below.  

Three-Phase Transformer Dialog

Single-Phase Transformer Dialog showing Half-Tap Impedance Factor.  

[__] TR kVA - defines transformer rating in kVA

 

[__] Half-Tap Imp Factor - For Delta-secondary transformers (only), defines factor applied to impedance value at half-tap position.
 

Enter TR Winding Z in:

  • Per Unit - sets dialog to use transformer winding impedance entries defined by Z in PU values.

  • Ohm - sets dialog to use transformer winding impedance entries defined by Z in Ohm values.

Z in PU:

[__] kVA Base - rated (apparent power) capacity of transformer

[__] kV Base - nominal transformer voltage

[__] Z Mag in % - impedance magnitude in percent

[__] Z Ang in Deg - impedance angle in degrees
 

[Update Ohms>>] - calculates the "Z in Ohm" R and X impedance values based on current "Z in PU" entries, allowing user to see impedance input converted to ohm values.
 

Z in Ohm:

[__] R - defines resistance of transformer winding (in Ohms)

[__] X - defines reactance of transformer winding (in Ohms)

 

Side Referred to:

    • Pri - indicates that R/X entries are given as reflected to Primary side of transformer

    • Sec - indicates that R/X entries are given as reflected to Secondary side of transformer

 

Secondary Conductors:

 

Available Multiplex Constructions - select appropriate secondary conductor configuration from available listing.

 

Length [___] Ft - defined length of secondary run (in feet).

 

Available Commands:
 

[OK] - accepts transformer data and runs application (to generate report).

[Back] - returns user to the Distribution Transformer Connection dialog, which was described previously.

[Exit] - cancels execution of Secondary Fault Analysis and returns user to main drawing window.  

 

 

After the transformer and secondary line properties are accepted, the application generates the Secondary Fault Analysis Report for the selected location.

 

Available Output Variables:

For general details on running an application, selecting and displaying output variables, see Running DEW Applications.  There are no output variables available for display from the Secondary Fault Analysis application.  

 

Variable

 

Description

N/A

-

Secondary Fault Analysis results are only viewed from the generated report (Secondary Fault Analysis Report).