See Also
The Fault Analysis dialog can be used to perform a fault analysis study on the currently loaded power system. A fault study can only be performed while Simulator is in run mode, since the load flow must be validated and solved before a fault study can be calculated.
If you are observing single fault analysis results in the fault analysis dialog and switch to edit mode, the dialog will automatically be closed and the single fault analysis results will be cleared from memory. Multiple fault results displayed in the Fault Definitions table are maintained when switching to edit mode, but may no longer be relevant when switching back to run mode, depending on what was done to the power system data in edit mode.
The fault analysis has two choices for calculating fault results. The first option is calculating the fault current at multiple defined points for a general summary of several faults, and the second is calculating detailed fault results and fault current flows for a single fault point.
Simulator stores fault data in the PowerWorld binary file along with the load flow data, but by default most other load flow formats store fault data in separate files. The fault data can be stored in and loaded from an external file, but if no fault data is present in a PowerWorld binary file or loaded from an external file before a fault analysis is run, Simulator will use the load flow data as default values for the analysis. Fault data values can also be modified for specific devices by opening a specific device's information dialog and looking at the Fault… tab. Devices that require sequence specific data for fault analysis are buses (for sequence load injections), generators, switched shunts, transmission lines, and transformers.
Phase shifts in a fault analysis calculation can be very important for calculating the correct fault currents and voltages throughout the system. The phase shifts that are applied for transmission lines and transformers are taken from the load flow values of phase entered with each specific transmission element. While transformers can have their transformer configurations specified (i.e. Delta-Wye, Grounded Wye-Delta, etc.), these configurations are NOT used to determine phase shift angles, ONLY to determine the proper grounding on each side of the transformer. The phase shifts that are applied are taken from the load flow data phase values for the transmission elements. If no phase shifts are entered in the load flow data, the fault analysis will treat all elements as having zero phase shift. Phase shift values can be entered manually for each transmission element, but are also included in most load flow formats and will be read into Simulator when loading a load flow data file.
Note that the bus chosen for the fault is always set to a 0 degree reference, and all other buses are shifted according to this reference.
Auto Insert...
Auto-Insert faults options similar to those in Auto Insert Contingencies in the Contingency Analysis dialog. Choose between a Single transmission line or a Single Bus. Then hit Do Insert Fault Records to insert the faults.
Load Data.../Save Data...
These two buttons allow loading from and saving to external files. Currently the two types of files supported are PSS/E Sequence Data files (.seq) and PowerWorld Simulator Auxiliary files (.aux). Either one of these formats can be loaded and saved.
Note that typically Simulator assumes that if no zero sequence data is given for a branch that the zero sequence impedance is defaulted to 2.5 times the positive sequence impedance. However, in the case of reading in data from a PSS/E sequence data file, you are given the option to instead treat branches with now explicitly given zero sequence data as open circuits in the zero sequence network.
Also can optionally append sequence data when loaded from the Fault Analysis dialog. A prompt will be given to clear all sequence data first or append if opening an auxiliary file or a PTI *.seq file where the *.seq file contains a 0 indicator for new data. If the *.seq file contains a 1 indicating that data should be appended, no prompt is given and the data is just appended.
Units
Select p.u. or Amps to show the current results in the selected units.
Inserts a temporary bus to represent the fault location in a Branch.
When defining multiple faults (like when using Auto Insert...) you have the option to specify the position of the fault along the line. To save computation time, by default a location >= 50 assumes a fault at the To Bus and < 50 assumes a falut at the from bus. Selecting the checkbox will add a dummy bus at the actual fault location.