See Also
Pre-Fault Profile
Changing this option determines the pre-fault voltage profile to be used for the fault analysis calculations. The pre-fault profile selection affects the sequence Y-bus values, fault currents, and post-fault voltages.
Profile Options
Additional pre-fault profile options are available when the pre-fault profile selected is either Flat IEC-909 or Flat Classical.
XF Turns Ratios Set to 1 If checked, all transformer tap ratios are assumed at their nominal tap position.
Line Charging Set to 0 If checked, line charging capacitance is ignored in all calculations.
Shunt Elements Shunt elements (bus and line shunts) can optionally be treated normally, ignored in the positive sequence only, or ignored in all sequences.
IEC Parameters This option only applies to the Flat IEC-909 pre-fault profile. The pre-fault voltage magnitude can be specified for each bus. In addition, a generator power factor angle (in degrees) can be specified for use when generator currents need to be calculated based on bus voltage and power (real and reactive) delivered by the generator.
Oneline Display
The string grids in the single fault dialog will display the fault results in tabular format, but the results can also be viewed graphically on the oneline diagram by selecting an option from this group of options. Any of the three phase values can be selected for display individually, or all three phases can be viewed simultaneously. Viewing all three phases of information simultaneously can result in an abundance of information on the diagram at one time, so selective placement of the necessary bus and line fields may need to be considered when planning on viewing the fault analysis results graphically on the oneline diagram.
The fields necessary on the oneline diagram for display of the fault analysis results are:
- Bus Voltage and Bus Angle fields need to be present for a bus. When choosing to view fault analysis results, these two fields will be identified, and the actual load flow values will be replaced by the fault phase voltages (in per unit) and angles (in degrees).
- AC Line MW Flow and AC Line Mvar Flow fields need to be present for a line. These two fields will be identified, and the MW and Mvar values will be replaced by the fault phase current magnitudes (in Amps or per unit) and angles (in degrees).
- Gen MW Output and Gen Mvar Output fields need to be present for a generator. These two fields will be identified, and the MW and Mvar values will be replaced by the generator terminal fault phase current magnitudes (in Amps or per unit) and angles (in degrees).