Simulator 16 User Guide - PowerWorld

Step Size
Increment between voltage set-points used to trace the curve for this particular bus. If this is not
specified, the default step size set with the default options is used. Only non-default values will be
shown. If the value is changed to the default setting, the cell will be set blank.
Modify Selected Buses to Select Only Singe Bus Per Super Bus
This button will only be visible if the Integrated Topology Processing add-on is available. When using
topology processing, only a single bus per super bus will be in the consolidated case. That means
that the parameters for each bus in the super bus will be the same, i.e. same voltage magnitude and
angle, etc. This button can be used to eliminate any excess QV curves that would just take up
computer memory by drawing essentially the same curve multiple times for the same super bus. To
take advantage of this option and only select a single bus per super bus, first set up the bus
selection to monitor all of the necessary buses and then push the Modify... button. The Selected
field in the table will then be updated to only include a single bus per super bus. When determining
the primary node (the primary node is the bus that will ultimately be the one monitored during the
analysis) and super buses, the active defined contingencies will be used to determine how the case
is consolidated. Because the consolidation can be different based on the contingency set, or lack
thereof, it is best to just define the selected buses to include all necessary buses and use this option
to refine the list down to a single bus per super bus rather than manually trying to maintain such a
list.
Buses can also be selected for analysis by using several options found at the bottom of the dialog. A
range of bus numbers or the name of a bus can be specified in the appropriate boxes. Clicking
the Add button for either entry will set the Selected? field to YES for the designated buses. These
options are used to make setting the Selected? field more convenient.
There is another set of options that will have the QV tool determine which buses should be analyzed in
addition to those already selected.
Additionally, automatically draw curves for
Check this box to optionally draw additional curves based on certain conditions. Set the number of
lowest-voltage buses and/or highest dv/dq buses at which curves should be traced. The dv/dq
sensitivity is the sensitivity of voltage at a bus to an injection of reactive power at the same bus. The
sensitivities are ranked based on their magnitude. These lowest-voltage buses and highest dv/dq
buses are determined for each scenario once any contingency has been applied. Use the from limit
group drop-down to specify which buses should be considered when evaluating these conditions.
Only buses that are assigned to the selected limit group will be considered.
If the buses identified when evaluating these conditions already have been selected by the user, no
additional buses will be selected to make sure that the number of additional buses to include is
achieved by buses that have not been user selected.
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