Simulator 16 User Guide - PowerWorld

The area control error in MW. This is the amount of MW flow difference between the actual MW
interchange and the desired MW interchange. A positive value means the super area is generating
and exporting excess MW's, and a negative value means the super area is under-generating and
importing too many MW's.
Lambda
The area’s marginal cost. This marginal cost is relevant only when an Economic Dispatch (not OPF)
solution has been run. Theoretically, if losses are ignored, an area operates most economically if all
generators operate at the same incremental cost. This common incremental cost is the area’s
lambda, or marginal cost.
The local menu of the area records display has an additional option labeled All Area Gen IC Curves.
Select this activity to generate a plot showing the incremental cost curves for all units located in a
particular area.
Loss (MW)
Total real power losses for the area.
Losses for tie-lines between areas are assigned to the area in which the terminal bus that is NOT the
metered bus is contained. The Metered End field for a branch determines which of the terminals is
metered.
Auto Shunts
Determines whether switched shunts for the area are available for automatic control. You can use
this field to disable all the switched shunts in an area. Click on this field to toggle its value. Click on
the Toggle All Yes or Toggle All No local menu options to set the auto shunts property for all
switched shunts. Note that a switched shunt is available for automatic control only if it meets three
conditions: 1) its control mode property is set to Automatic (see Switched Shunt Information
Dialog); 2) its associated area’s Auto Shunts property is set to Yes; and 3) the Disable Switched
Shunt Control option on the Power Flow Solution tab of the Simulator Options Dialog must not be
checked.
Auto XF
Determines whether tapped transformers for the area are available for automatic control. You can
use this field to disable all the transformers in an area. Click on this field to toggle its value. Click on
the Toggle All Yes or Toggle All No local menu options to set all entries in this column. Note that
three conditions must be met for a transformer to be used for automatic control: 1) its Auto field
must be set to Yes (see Transformer Modeling for details); 2) its associated area’s Auto XF property
is set to Yes; and 3) the Disable Transformer Control option on the Power Flow Solution tab of the
Simulator Options dialog must not be checked.
Unspec. MW Inter.
Shows the total amount of interchange for the area that is listed as Unspecified. This means that
some of the interchange is known in magnitude and direction (import or export) but not which other
area(s) is involved in the interchange. The sum of all area’s unspecified interchange in the case must
equal 0 for a balanced system.
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