Power System Description (PSD)

This short description gives you information on the following topics:

 

 

 

 

 

 

 

 

 

 

 

 

Modelling a Power Distribution System with PSD

Procedure for creating a new project

The Power System Description (PSD) offers you three views of your data:

First of all, create your networks in the Network configuration view and make the appropriate settings.

Then change to the Substation configuration view to create your substations there. First enter the busbars within a substation. You must immediately assign a network (and thus a voltage level) to each busbar.

Then create the corresponding Feeders in the level below the busbars. Every feeder represents a measuring point in this model.

The feeders are required:

A complete feeder parameterization includes the assignment of measuring channels for current and voltage measurement. Configuration is possible, however, only if the respective devices are provided in PSD (see Parameterization the devices).

To be able to perform a fault location, you must parameterize the lines. This is done in the Network configuration view.

Once you have created a line below a network object, the line parameters can be entered. In doing so, you can choose between a single-ended or a two-ended fault location. In the case of a single-ended fault location, an optional parallel line compensation for double-circuit lines can be carried out (to do so, select the option Yes under the Double-circuit line).

A line can comprise of several sections with different impedances, for example, cable and overhead line. This is why PSD enables you to subdivide your line into several Segments with different characteristics.

Parameterizing the line sections

Various characteristic data of a line segment are required for fault location. Basically, it is a matter of impedance of the positive-sequence system, the earth impedance as well as the coupling impedance, as the case may be (if Double-circuit line has been set). There are several options for entering the impedances:

The input format is selected in the menu item Extras -> Options. To enter the coupling impedance, there is only one option with the ratios RM/RL and XM/XL. For the definitions of the individual values please refer to Appendix: Equation Symbols and Equations.

All impedances and matching factors are quantities per unit length (e.g., Ohm/km). Impedances referred to the primary side are required. You can choose between kilometres and miles as the unit of length. This setting can be made in the OSCOP P module Parameterize PC under the menu item Global -> Country settings -> Metric or US units. The setting applies to all OSCOP P modules.

If you change the input format or switch between kilometres and miles, values that have already been entered will be converted automatically.

You can enter the capacities in all input formats. The capacity values are calculated appropriately from the remaining impedances. We recommend the default setting (at least for overhead lines). If you want to enter the capacities explicitly, click on the corresponding value and overwrite the displayed text will be calculated with the value.

The equations for automatically calculating the capacities can be found in Appendix: Equation Symbols and Equations.

In addition to the line impedances, you can set several further parameters. The total length of the line is calculated from the lengths of the individual sections and is displayed in the general parameter table.

You can use the context menu to add further sections. To do so, click on the section number in the first column with your right mouse button. You can either create a new section with the preset values under Add segment or use an existing section as a template with Copy and Paste. The order of the sections can also be changed subsequently via the context menu.

Parameterizing the devices

At the moment, there is no option to create or parameterize the devices directly in the PSD configurator. For this purpose, you have to use the other OSCOP P modules (Parameterize PC for creating devices and Parameterize Devices for configuring devices).

Only the device parameters that are required for parameterizing the fault location are displayed in the PSD model. Basically, these are assignments of devices and measuring channels to other substation elements.

Notes on How to Configure Assignments

Measuring channel assignment for fault location

Assignment between line and feeder

Two-ended fault location

Single-ended fault location with parallel line compensation

Assigning a substation element (feeder or busbar) to a device or a device component

Upgrading from an Older OSCOP P Version

When installing OSCOP P, all the data from your old OSCOP P database is transferred. The database including all configuration settings is converted automatically to the new format.

The fault locator configuration ("V2 diagnostics") of an old OSCOP P version is compatible to the PSD configurator.

The following configuration elements are transferred automatically from an old project:

After you have transferred an old project, check the configuration data that has been entered automatically and complete it insofar as this is necessary.