Fault Analysis

DIgSILENT PowerFactory features three-phase network fault calculation functionality based on international standards as well as the most accurate DIgSILENT General Fault Analysis (GFA) method.

In general the following features and options are supported for all implemented fault analysis methods:

Includes calculation of all three symmetrical components as well as phase quantities.
User definable fault impedance
Calculation of short circuit quantities at a specific, selected busbar or along a defined section of line/cable, including all branch contributions and busbar voltages.
Provision of specially designed graphs and diagrams including all quantities typically required by the protection engineer.
Thermal overloads highlighted on the single line graphic for busbars and cables, with all equipment overloads available in a summary text report.
A complete power flow output, including branch currents and busbar fault voltages, can be displayed for all branches and nodes, or selected busbar subsets.
Calculation of Thevenin impedances as seen from the faulty node.
Calculation of apparent phase impedances (magnitude and angle) at any location along a transmission line/cable or busbar, for all branches, selected subsets, or 1,2 or 3 nodes from the faulted node.

IEC 909 and VDE 102/103 Fault Calculation

For the world-wide most frequently used standard for component design, PowerFactory provides a strict and complete implementation of the IEC 909 and VDE 102/103 fault calculation standard according to the latest published versions.

Calculation of the initial symmetrical peak current Ik" and short circuit power Sk", peak short circuit current Ip, symmetrical short-circuit breaking current Ib, and thermal equivalent current Ith (IEC 60909-0 2001). Both minimum and maximum short circuit currents can also be calculated based on network voltage c-factors.
Support of all fault types (balanced and unbalanced)
Automatic grid type identification
Calculation of Ik with selectable "Decaying Aperiodic Component"
Selectable method for calculating the Peak-Short Circuit Current in meshed networks
User definable fault impedance, conductor temperature and c-voltage factor.
Fault calculation can include or exclude motor contribution to the fault current.
Provision of specially designed graphs and diagrams required by the protection engineer for protection coordination and design.

IEEE 141/ANSI e 37.5 Fault Calculation

PowerFactory provides a strict and complete implementation of the IEEE 141/ANSI e37.5 fault calculation standard according to the latest published version. Special features are:

Transformer tap positions can be included in the fault current calculation.
User defined fault impedance and pre-fault voltage can be included in the fault current calculation.

DIgSILENT General Fault Analysis (GFA)

Especially for protection coordination purposes or for analyzing observed system contingencies, the DIgSILENT PowerFactory General Fault Analysis (GFA) is providing the required algorithms and precision for determining the "real" short circuit currents without considering the typical simplifications or assumptions typically applied for norm based fault analysis. The General Fault Analysis (GFA) is based on an unconstrained sub-transient power flow, and takes into account all specified network devices with their full representation and pre-faulted load conditions. The general fault analysis tool is based on a complete 3-phase system representation (a-b-c phase coordinates). The analysis of multiple fault conditions is one of the most important features of the GFA.

Additional features are summarized below:

Calculation of any asymmetrical, single or multiple fault conditions with or without fault impedance, including single and double phase line interruptions.
The initial response of many other "event" like motor starting, generator tripping, shunt switching, load shedding, etc., may be analyzed (stability module required).

Fault Analysis Results

Various reports may be produced, including detailed reporting on all short circuit levels for all faults, or alternatively, a specific report for one fault type. Special protection reports can also be generated to include impedance, current and voltage information.
Display of any variable within the single line and station diagram according to a most flexible VI definitions.
Fully flexible filter mechanisms to display objects in colored mode
Detailed analysis reporting, which can list overloaded system elements, unacceptable fault currents, islanded system areas, out of service components, voltage-levels, area summaries, and many other documentation features.
Detailed text output with pre-defined or user-defined filters and levels.
Support of the Flexible Page with free variable definition and DPL interactivity.
Result export to other software system such as MS-EXCEL