Files,
Extensions, and Supported Formats
Diagrams
Case
Information Displays
Contouring
Options/Environment
Time
Step Simulation
Distribution Factors, Sensitivities, and Generation Shift Factors
GIS Tools
Auxiliary
(aux) Files
Reports ,
Presentations,
and Movies
Contingency
Analysis
Power Flow Solution and Other Calculations
Simulator Add-ons (ATC, OPF,
SCOPF, PVQV Curve Tool, SimAuto)
Are the one-line diagrams easy to
build?
We think so! We've gone to great lengths to make it easy to
build diagrams.
You can specify default drawing values for display objects based on
object type and nominal kV. These values can also be saved to or
loaded from auxiliary files providing continuity when creating
multiple diagrams.
If
you have geographic information regarding the location of
the buses in your system, you can automatically insert the buses at
the prescribed locations. Then just use Simulator's built-in features
to automatically insert lines, generators, and loads to create the
rest of the
diagram.
Additional features such as the ability
to select and format multiple objects simultaneously and the ability to "anchor"
objects to buses and lines make it easy to build and modify the
diagrams. (When an object is "anchored" to either a bus or a
line, moving the bus or line on the diagram causes all the objects
anchored to the object to move with the bus/line; this feature is
essential when attempting to rearrange objects on your diagram.)
Please see Simulator Tips: Creating
and Modifying Diagrams for more information.
Alternatively, you can
import diagrams saved in a common power flow one-line drawing
format.
We also provide diagram development services for a very reasonable fee.
Contact us at info@powerworld.com
for information.
Finally, Energy
Visuals (a sister company of PowerWorld Corporation) develops and
markets the product Transmission Atlas. Transmission Atlas provides
very large one-line diagrams built from common models such as the WECC,
ERCOT and NERC MMWG models of the United States. These diagrams include everything in the case at 69 kV and higher, and all
generation with at least 50 MW maximum output.
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How do I
show
animated flows on the
diagrams? Can
the
animations
be
customized?
Check
the box marked Show Animated Flows on the Animated Flows tab of
the Oneline Display Options dialog (select Options >> Oneline
Options from the main menu to open the dialog). Yes,
the animated flows are easily customized via the
Animated Flows tab of the Oneline Display Options dialog.
Customization options
include:
-
Size
-
Color
-
Shape
-
Density
-
Animation
Parameter (actual flow or percent flow)
-
Whether
or not the animation symbols move
-
Flow
Visualization type (Show MW, Mvar, PTDF, or combinations of these
simultaneously
on a diagram.)
-
Symbol
type (arrows, circles, squares)
-
Animation
Rate
-
Symbol
Fill Color
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Are zooming and panning supported on the
diagrams?
Yes, you can easily zoom and/or pan the
diagrams.
Additionally,
display objects on
the
diagram
can be set so that they are only visible at certain zoom
levels. This allows you to zoom into a portion of the one-line and
show successively more detail as you zoom in.
A find command is also
available to allow you to easily locate a particular bus on the
one-line.
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What are contours
and how can I use them?
Simulator has the ability to contour the system parameters on the
one-line diagram. The output of the contouring is a plot very similar
to the temperature contours seen in the newspaper, except a system
parameter, not temperature, is being contoured. This feature can be
extremely useful for rapidly assessing power system conditions in a
large region. For example we have one client that has a contour of
more than 4000 bus voltages which is updated from real-time data
approximately every minute. Using this one-line in conjunction with
our OPF add-on, you can use contouring to show price profiles
throughout the U.S.
See our Features page for an example
contour of marginal bus prices.
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Can the Simulator displays be pasted into other programs, such
as PowerPoint? What other presentation features are offered?
Yes. The one-line diagram contains a local-menu with a command to
copy the display into the Window's clipboard. From there you can paste
it just about anywhere, including into a word processing or
presentation program.
Simulator also provides a movie maker tool. Users can create
either mpeg or avi movies that will play on any standard media player
to present simulation results to an audience .
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What is the
difference between the *.PWB and *.PWD files used by Simulator and what
are PowerWorld Project Files?
PWB and PWD stand for
PowerWorld Binary and PowerWorld Display.
The PWB files contain the
actual power system data for the case. Traditionally, case files can
contain large amounts of data. We store this data in a binary file to
reduce the size of the file on your hard drive. Furthermore, data stored
in a binary file may be read much more rapidly than a text file,
allowing Simulator to load large cases more quickly.
The PWD files contain the
graphical data associated with the case. In other words, the sizes,
shapes, colors, and locations of the graphical elements of the one-line
diagram are stored in the display file. One common misconception is that
the display files contain power system data. They do not. All power
system data is stored in the PWB file. Bus Numbers serve as the key for
our display files, allowing them to link with the power system data
after they are opened.
Simulator splits case and
display data into two files so that one-line diagrams can be used with
many different cases.
PowerWorld Project files
end with the extension *.PWP.
In Simulator, it is not
unusual to have a number of files associated with one power system case.
In addition to the case file that stores the model of the system, there
may be one or more diagrams depicting various regions of the
system. These diagrams might feature document links that connect to
files that were created using other applications. Other files such as
template files, auxiliary data files, and script files might also be
associated with a Simulator case. While keeping these files separate
makes maintaining the data easier, it may make it difficult to transfer
the case to another computer, or to share the model with a colleague.
PowerWorld Project files provide you a solution by combining all the
files associated with the case into one file. In order to a create a
project file, open the case for which you want to create the project in
Simulator. Then open any one-line diagrams that you wish to open
automatically when the user opens the project. Then select File >>
Save As Project, from the main menu to open the Create Project Dialog
which allows you specify the contents of the project file. Finally click
OK to create the project file. For more details see the Simulator User's
Guide (PDF, opens in new window).
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How do I
select and format groups of objects on a diagram?
You must be in Edit Mode to
format objects.
To select a single object, left-click on the object. You can then format
the object by using the options available from the Format menu.
To
select multiple objects use Shift Select, Select Region, or Select by
Criteria (see below); then use the options available on the Format menu
to format all selected objects simultaneously.
Hold down the Shift
key then left click on each object you wish to select. If you want to unselect one of the objects you have selected,
continue holding down the shift key and click on that object again.
Click the Select Region
button 
from the edit toolbar or choose Edit >> Select Region.
Next, click and hold down the left mouse
button then drag your cursor to create a rectangular region. Let go of
the left mouse button and all objects inside the region will be
selected. Note: a diagram must be the active window in order
to use this tool. If (for example) a case information display is
the active window, the Select Region option and toolbar button will be
disabled.
The Select by Criteria
dialog allows you
to select multiple objects based on options such as object type, area,
zone, layer, nominal kv, etc... For example, you could use this
tool to select all transmission lines, transformers and line flow pie
charts in area ABC having nominal voltages between 200 and 300
kV.
Click the
Select by Criteria button 
on the edit toolbar, or choose Edit >> Select by Criteria
to open the dialog. Note: a diagram must be the active
window in order to use this tool. If (for example) a case
information display is the active window, the Select by Criteria option and
toolbar button will be disabled.
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Some
of my toolbars disappeared. How do I get them back?
The toolbars in Simulator
can be dragged around the screen or docked on the left, right, top, or
bottom of the Simulator window. When a toolbar is dragged into the
middle of the screen, an X appears in the top right of the toolbar. By
clicking on the X, the user can close the toolbar.
In order to make a toolbar
reappear after it has been closed, right-click on one of the other
toolbars to bring up a list of the available toolbars. The ones which
are presently visible have a check next to them. Choose toolbars without
a check to make them visible. You can also get access to this menu by
choosing Window >> Toolbars from the Simulator main menu.
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How do I copy
and paste from Simulator case information displays?
PowerWorld Simulator can do
a lot, but how would you like to extend Simulators abilities to include
all the power of a spreadsheet application such as Microsoft Excel or
Corel Quattro Pro? To copy and paste from case information
displays, right-click on the display and use the options in the
resulting local menu. For more information see: how to use key
fields, creating new records by pasting data, and the cut/paste
example
provided in
Simulator Tips.
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How
do the key fields and required fields for aux files and copy/paste from
Excel work?
Each object type in
Simulator (i.e. Loads, Generators, Buses, etc...) has a number of key
fields and additional required fields. Key
fields are fields that must be included for existing records when
pasting data into Simulator from a spreadsheet application such as MS
Excel or when loading information from an aux file. Required
fields are fields that must be specified (in addition to key fields)
when creating new records by pasting data or loading from an aux file.
For
example, when pasting data for an existing load record, the bus number
and ID (key fields) must be specified with the pasted record in addition
to any other field the user is modifying with the pasted data.
When creating a new load record, however, the user must paste the load
Status, S MW, and S Mvar (required fields) in addition to the above
mentioned key fields (click here for more
information on creating new records via aux files or by pasting data in
from spreadsheet applications.) The easiest method of determining
key/required fields for an object type is to open a case information display,
right-click on a record and select Display/Column Options from
the resulting local menu. Check the box labeled Highlight Key
Fields on the resulting dialog that opens. Key fields are
highlighted in yellow, required fields are highlighted in
green. Simulator
uses variable names (vice normal column headings) when reading in data
from an aux file. There are a number of methods to determine the
variable names you should use in your aux files. The easiest
method is:
-
Open a case in Simulator
then open a Case Information Display for the object type you are
going to import via the aux file.
-
Select Options
>> Solution/Environment from the main menu.
-
Click on the Case
Information Displays tab.
-
Select "Use Variable
Names" in the section labeled Column
Heading Options.
-
Click OK to close
the options dialog.
-
Right-click on the case
information display then select Save As >> Auxiliary File from
the resulting local menu.
-
Specify the file name and
directory path in the Save As dialog and click Save.
-
Open the file you just
created in any text editor and use that file as a template to create
your aux file.
You can
also select Help >> Export Object Fields from the main menu
to obtain either a text file or Excel worksheet listing all available
object types by variable name and their corresponding object fields with
key and
required fields annotated. One
final note: new object records can
only be created in Edit Mode. If you attempt to create a new
object while in Run Mode, Simulator will not create the record and
the message log will display one of the following messages:
"Data for (x) records not pasted" or "(x) records
skipped when reading file because the object could not be
found" where x is the number of new object records you
attempted to create.
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How
do I create a new record by pasting in data from another application?
To create a new record by
pasting in data, you must:
-
Be in Edit mode
-
Ensure that you include all
key
fields and required fields for the object type you are
creating.
-
Ensure the format of the
pasted information is correct (see Required Format below).
-
Place the data to be
pasted on the clipboard by highlighting the data in your spreadsheet
application and selecting either Cut or Copy.
-
Right-click in the Case
Information Display and select Paste.
If you pasted the data
correctly, you will be asked to confirm that you want to create a new
record. Please note that if all key and required fields are not
specified, or if you are not in Edit Mode, the new record will not be
created.
You can view the paste
results in the message log.
Required format:
The first row, first column contains a description of the data (i.e.
Load Record). The remaining columns in the first row should be
empty. The second row contains the column headers specifying
what information is contained in a given column. Simulator reads these rows to determine how to
treat the incoming data. (Note that if Simulator does not
recognize a heading, it ignores the rest of the paste.) The
remaining rows each contain one object record. For more
information, see the example
in Simulator Tips.
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When
I pasted in (or imported from an aux file) information for a generator record, the AGC field changed to "NO". Why is
this occurring and how do I correct it?
This is an option on the
Environment tab of the Solution/Environment Options
dialog.
If a value is
pasted in for Gen MW, then Simulator assumes that you desire to have
Gen MW specified. As a result, Simulator automatically sets
the AGC field for that machine to "NO."
Additionally, when importing data either from an aux file, or from a
spreadsheet application, Simulator updates each field in the order
it was received. The consequence of this is that even if you
set the AGC field to "YES", but subsequently specify a
value for the Gen MW field, Simulator sets AGC back to
"NO".
There are a number of
methods to retain the AGC field as "YES" when pasting or
importing Gen MW values:
-
Manually set the AGC
option back to YES after pasting the record, or
-
Include an AGC
column after the Gen MW column in the pasted data with
the value set to "YES", or
-
Select Options
>> Solution/Environment from the Simulator Main
Menu. On the Environment tab uncheck the box
marked "Disable AGC When Manually Changing Generator
MW."
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What tools do you offer for
developing reports and
presentations from PowerWorld applications?
The one-line diagram contains a local-menu with a command to copy the
display into the Window's clipboard. From there you can paste it just
about anywhere, including into a word processing or presentation
program. You can also use the Print Screen option, which is
standard in Windows operating systems, to produce image files of screen
shots.
Other presentation features include a web publishing tool and a movie
maker tool.
- Simulator provides several tools for saving a variety of data in a
web-friendly format. You can save images as jpeg files, and all case
information displays can be saved as HTML tables. You can then integrate
these files into a single web document using the PowerWorld HTML editor,
which is included with all versions of Simulator and Retriever. Finally,
you can upload the HTML document, together with any necessary
attachments, to your web server.
- Use the movie maker tool to create mpeg or avi movies (playable on
any standard media player) to present simulation results to an audience.
Top
How do I copy
Simulator one-lines or dialog boxes to put in my reports and
presentations?
Copying Simulator
one-lines
Simulator one-lines provide
outstanding graphical visualization capabilities. The diagrams created
convey a wealth of engineering and economic information in an easy to
understand format. For this reason, our customers are always interested
in copying these graphics into other Windows applications such as a word
processor or presentation program. The best way to copy a Simulator
one-line diagram is to right-click on the background of the one-line and
choose Copy Image to Clipboard. This will copy the one-line to the
Windows Clipboard as a Windows Metafile (*.wmf). Windows Metafile's are
the standard format of the Windows Clipboard. Then to paste the one-line
into another application, such as a word processor, simply open up the
application and choose Edit >> Paste.
Copying Dialog Boxes or
Anything on the Screen
Windows provide the ability
to copy the entire monitor screen to the Windows clipboard as a bitmap.
Simply press PrintScreen on the keyboard to do this (this key is
normally to the right of the F12 key). To paste the image into an
application, open the application and choose Edit >>Paste,
or right-click and select Paste, or press Ctrl+V (if
supported).
Windows also provides the
ability to copy only the presently active window to the clipboard by pressing
Alt+PrintScreen.
Note: Alt+PrintScreen will
only copy either a "Child Window" or all visible windows in a
current application.
Child windows are windows that can not be moved outside the scope of
the application window.
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How does
Simulator convert transmission line flow between MVA and Amps?
Variables that are
calculated by a power flow are the MVA flow leaving a bus along a
transmission line and the bus voltage.
-The MVA flow is the total
MVA flow on all three phases of the transmission line (S3-ø).
-The voltage is the line-to-line voltage (Vline-line)
Current is only defined for
a single phase, so in order to determine the single phase current, solve
S1-ø = Vline-nuetral
* I (where I = current)
To convert the values the
power flow calculates to the ones in this equation, do the following
S1-ø = S3-ø /
3
Vline-nuetral = Vline-line / sqrt(3)
Thus we can write
S3-ø / 3 =
Vline-line
/ sqrt(3) * I
Which simplifies to the
equation used to determine the current on a transmission line
I = S3-ø / (
sqrt(3)* Vline-line )
Note: The same equation is
true for a transformer.
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How
do I modify the colors and general scheme of a large diagram?
New Diagrams:
You can set default drawing values by selecting Options >>
Default Drawing Values from the main menu.
Exisitng Diagrams:
Use the Select by
Criteria tool to select all objects meeting a specific criteria then
format the objects as a group.
See Select/Format
Multiple Objects or Simulator
Tips: Creating and Modifying System Diagrams for more information.
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Is
it possible to (How do I) build a large diagram quickly?
Simulator provides a number
of tools for rapid diagram creation. These include: insert
pallettes for areas, buses, substations, and zones, and the ability
to auto insert lines, interfaces, generators, switched shunts,
line flow pie charts, circuit breakers, line flow objects, buses,
substations, borders, and GIS data from shape files. For more
information on using these tools, see Simulator
Tips: Creating and Modifying System Diagrams.
Top
What power flow algorithm does PowerWorld use?
Simulator uses a full Newton-Raphson algorithm, with non-divergence
control. Simulator can solve power systems with up to 100,000 buses,
and an almost unlimited number of lines. Simulator has been used to
solve FERC 715 cases for all of the NERC (North American Electric
Reliability Council) regions. The largest cases we've seen so far have
been 65,000 buses cases developed by combining the Eastern
Interconnect, Western Interconnect and ERCOT systems in the United
States into one large case. PowerWorld Simulator offers the user the
Decoupled Power Flow and the DC power flow as solution options as well
as a "Robust Solution Process," which
iterates between the
various solution options in an attempt to solve very ill-conditioned
cases.
The power flow algorithm incorporates common controls used in power
flow analysis, including remote voltage regulation by LTCs,
generators, and switched shunts, shared voltage regulation by
generators, phase-shifting transformer control, DC line modeling, and
Multi-Terminal DC Line Modeling.
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How
do I get a case to solve when read from a publicly available text file
format such as a *.RAW or *.EPC file?
(Answer coming soon)
Top
How
do I set limit enforcement for use in an LP OPF solution?
(Answer coming soon)
Top
How
do I filter a case information display so that it only shows the
information I need?
You can filter case
information displays by Area/Zone/Owner and/or by applying a custom
filter (called Advanced Filtering). Area/Zone/Owner
Filters
To hide all records assigned to
a particular area, zone, or owner:
-
Click the Area/Zone/Owner
filters button 
on the case information toolbar or select Case Information >>
Area/Zone/Owner Filters from the main menu. The resulting dialog
has three tabs labeled Areas, Zones, and Owners. The controls on
each are the same.
-
Toggle the Shown
field to "NO" for the desired area, zone, or owner.
(Note: You can toggle all to NO or YES by right-clicking on the
display and selecting Toggle all NO/YES from the
resulting local menu.)
-
Close the dialog and note
that only the records belonging to areas/zones/owners whose Shown
field is "YES" are displayed on Case Information displays.
-
If the title of the Case
Info Display says "(ignore Area/Zone/Owner filter)" you can
activate the filter by clicking the Use Area/Zone/Owner Filters button
 on the Case Info
toolbar.
-
If the title of the Case
Info Display says "(filtered)" but it does not appear that
the display is actually being filtered, right-click on the current
case info display and select Refresh Display from the local
menu.
Advanced Filtering
To filter a case information
display further than Area/Zone/Owner filters allow, right-click on the
display and select Advanced Filter from the resulting local
menu. This brings up the Advanced Filters Dialog, which allows you
to custom filter the information in the display. Advanced Filters are
stored with your Power System Case.
To create an Advanced Filter you must specify the following things:
Filter Name
- A string that describes your
filter so that you can call it up from other forms in the future.
Condition 1, Condition2, etc… -Describes
the conditions of your filter. To define a condition
-
Specify the
field you are filtering. By default, the fields in the drop-down list
are limited to the fields presently shown as columns in the display.
If you wish to choose from a list of all fields for the object, change
the radio button setting to Show All
Fields.
-
Specify the
comparison operation such as "between" or "greater
than".
-
Specify the
values the field is compared to. Depending on the comparison
operation, either one or two values are needed.
-
Select ABS
to use the absolute value of the field value in the comparison
operation.
-
To add or delete conditions click
the Add >> or Delete…
button.
Note: The comparison operation "within
integer range list" uses the same format as described in Entering
a Range of Numbers. See the help files included with your software
for more information.
Logical Comparison - The following describes how the Filter uses
the Conditions which are specified
-
AND means
that all conditions should be true
-
Not AND is
the opposite of AND (i.e. any one of the conditions can be false)
-
OR means
that any one of the conditions can be true
-
Not OR is
the opposite of OR (i.e. all of the conditions must be false)
-
Important Note: once you choose
a condition comparison type, that type is used for all conditions in the
filter. Therefore if you wish to use the AND condition, all conditions you
define will be applied using AND. There is a way to combine different
conditions within the same filter. This is accomplished by allowing nested
filters. In other words, one condition of a filter can be that another
filter is met. To refer to one filter from within another, set the Field
of the condition to the last item in the list, labeled "_UseAnotherFilter".
Then choose whether the condition is to meet the filter or Not
meet the filter, then choose the filter (which must have been previously
defined) from the drop down list of the third box, or by clicking the Find
button.
Pre-Filter using Area/Zone Filters -
When this box is checked, data is filtered
first by the Area/Zone/Owner Filters
and then by the Advanced Filter, therefore the data must meet both filters
in order to be shown. When this box is unchecked, the Area/Zone/Owner
Filters are ignored.
Enable Field to Field Comparisons - When this box is checked, it is possible to
compare two fields. In order to do so, select Field
and click on Find to select the
second field to be compared.
A Case Information Display will have the phrase "(advanced
filter)" in its caption if an Advanced Filter has been applied to it.
To remove a filter from a Case Information Display, open the Advanced
Filters Dialog and and click on Remove.
Note that Remove does NOT delete the filter, but just stops using it to
filter the data. You can always remove the filter temporarily and then
come back into the Advanced Filters Dialog and reapply the filter. If you
want to Delete a filter, you must bring it up in the Advanced Filters
Dialog and click Delete.
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How
do I prevent
contours from bleeding into the ocean (or other regions on the diagram)?
Answer:
Use stack levels. Create a filled, solid object
in the background stack level to provide a boundary for the
contour. Explanation:
PowerWorld diagrams have four different stack levels: top, middle,
background and base. Objects in higher stack levels have display
priority when multiple objects fall in the same location on a
diagram. That is, if two display objects overlap or occupy the
same location on a diagram, the object in the higher stack level will be
the one that is displayed in the overlap region. This occurs
because when the diagrams are drawn on the screen, the base stack level
is drawn first, followed by contours, then background, middle, and
finally top. The top and middle levels contain objects associated with
the power system data (such as breakers, pie charts, buses, generators,
etc...) Borders default to the background stack level. Contours
appear between the background and base levels. Borders are
typically visible on contoured diagrams because their default stack
level (background) is drawn after the contour is drawn. If a
border object is assigned to the base stack level, then it will be
hidden by contouring. Method:
Create a solid (closed) drawing object, apply a fill color, then
assign it to the Background stack level.
- To do this using existing PowerWorld library borders, split and merge the borders to create a single object comprising
the boundary of the area from which you wish to exclude the
contour. Click here for
information on splitting and merging borders. (Note: the
object must be a closed object in order to apply a fill color.
You will have to add additional line segments after merging the
desired borders to accomplish this.)
- Select the newly created object by left-clicking on the object.
- Select Format >> Line/Fill from the main menu then
specify the desired fill color. (Note: You must specify a fill
color in order to hide the contour)
- Click the Levels/Layers tab on the Format dialog then
select Background for the Stack Level option.
- Finally, since the newly created object was created from existing
borders, it is assigned to the "Borders" layer. You
may wish to reassign these objects to a new layer to make
your diagrams easier to handle. On the Levels/Layers tab of
the Format dialog, click the Add New button in the Layers
Section. Enter a name for the new layer (such as "Contour
Boundary") in the Add New Layer dialog, then click OK.
- Click OK on the Format dialog to close the dialog and apply
your changes.
Final note: If you wish to have a contour fully contained within a region, you
will have to create a non-filled solid object inside of a filled,
background level object - rather like the hole in a washer.
The contour will be visible in the non-filled portion, but hidden by
the filled portion
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How
do I quickly hide and show display objects on my diagram?
There are a number of options
for hiding or showing objects. Choose between the use of Screen
Layers, One-line Views, Keyboard Shortcuts, Conditional Displays, and Dynamic Formatting to
control the display of objects. Please see Simulator
Tips: Show/Hide Display Objects on Diagrams or the help files
included with your software for more
information.
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How
can I get quick access to the many options on the Options,
Solution/Environment or Oneline Display Options dialogs?
Toolbars!!! Most
options available via Simulator Options dialogs are also contained on
toolbars. Simulator offers more than 15 different toolbars
accessible by right-clicking on any visible toolbar then selecting the
desired toolbar. In addition, our toolbars are fully customizable
(right-click then select "Customize") and able to be floated
or docked virtually anywhere in the application window.
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How can a branch PTDF be greater than 100%?
Normally, we would not expect any branch PTDF for a transfer to be greater than 100%.
However, values larger than 100% may occur on branches with negative reactance, such as
series capacitors.
The illustration below shows PTDF flows for a transfer between the
right bus and the left bus. The line directly connecting these two buses
has a negative reactance. The PTDFs flow back to the right bus on the
parallel path through the bottom bus, which has a positive reactance.
Note that if we create a "network cut" at the lines attached
to the left bus or to the right bus,
we still see a net 100% PTDF flowing from source to sink.
Top
Is
it true that the lossless DC PTDF values are affected by neither the
voltage/angle solution, nor the generator outputs?
(Answer coming soon)
Top
How
does the resistance value (R) of transmission lines affect the DC PTDF
calculations?
(Answer coming soon)
Top
What
is the difference between the PTDF and the GSF/TLR calculations?
(Answer coming soon)
Top
How
do I reroute transmission lines on a diagram? You
can only route transmission lines while in Edit Mode. Hold down
Ctrl then left-click on a line to
add a vertex to the line. Once the vertex has been added, you can
click and hold the left mouse button to drag the vertex to the desired
location. To
delete a vertex, hold down Ctrl and left-click on the desired
vertex.
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How do I display a border for a region
(such as New England, or the Southeastern United States) without
displaying the individual state (county/country/province)
boundaries inside the region? Use
the Split Background Line and Merge Background Lines options
available by right-clicking on the desired object(s). The idea is to
split the borders at the vertex points where one border object (such
as a state) meets an adjoining border object, then to merge all of
the newly created individual lines to create the boundary for the
region you desire. Finally, go back and delete the interior
borders lines that you do not wish to display. See Converting
Background Lines in the help files for more information on
splitting and merging lines.
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Can
I compare two lists of contingency results?
Yes.
In the contingency analysis tool, you can set a controlling and a
comparison contingency list. Simulator will add several new columns to
the contingency analysis grid to display comparison results for the two
lists.
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Why
do the rotors of the generators do not spin anymore?
The rotors can be set to
spin by editing the display options. Select Options >>
Oneline Display from the main menu. On the display options tab
of the oneline display options dialog, there is a field labeled
"Change in Gen Rotor Angle per Refresh (degrees)" If the
value is set to zero, the rotors appear stationary when the diagram
animation is in motion. This value can also be set on either the
Miscellaneous Options drop-down menu of the Oneline Options toolbar or
by selecting Options >> Oneline Display >> Misc. Options (satellite
menu) then specifying a value in the Gen Angle Change field.
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Can
I simulate Electricity Markets with Simulator?
Simulator
is an ideal tool to analyze electricity markets. Based on generator
bids, load benefit curves and full modeling of the transmission grid,
Simulator OPF/SCOPF allows you to determine security-constrained LMP’s
at every bus in the system, and thus determine how much the market
agents will have to pay or be paid in the market. Simulator will allow
you to minimize system operating cost, to enforce security constraints,
and to determine the effect of congestion and re-dispatch. You can use
Simulator to determine, reproduce and forecast marginal prices, which
will help you design the best strategy to operate your assets in the
market. Using Simulator Time Step Simulation tool, you can obtain the
system optimal dispatch and LMP's for a number of hours, and see how
prices change with demand or system conditions. Furthermore, you can
visualize LMP's on your oneline diagrams and obtain great insight about
the spatial behavior of marginal prices, congested paths and even detect
market power.
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How do I determine the variable
names to use for a particular object field in an aux file?
Simulator
uses variable names (vice normal case information display column headings) when reading in data
from an aux file. Case Information Displays can be configured to
display either normal column headings, or the variable names used
internally by Simulator. The easiest
method of determining the
variable names you should use in your aux files is:
-
Open a case in Simulator
then open a Case Information Display for the object type you are
going to import via the aux file.
-
Select Options
>> Solution/Environment from the main menu.
-
Click on the Case
Information Displays tab.
-
Select "Use Variable
Names" in the section labeled Column
Heading Options.
-
Click OK to close
the options dialog.
-
Right-click on the case
information display then select Save As >> Auxiliary File from
the resulting local menu.
-
Specify the file name and
directory path in the Save As dialog and click Save.
-
Open the file you just
created in any text editor and use that file as a template to create
your aux file.
You can
also select Help >> Export Object Fields from the main menu
to obtain either a text file or Excel worksheet listing all available
object types by variable name and their corresponding object fields with
key and
required fields annotated. See also: PowerWorld
Auxiliary File Format (PDF, opens in separate window)
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How
do I animate flows without continuously solving the power flow?
Select Options >>
Solution/Environment from the main menu. Check the Display
Only option on the Oneline tab of the resulting dialog then
click OK. Next, select Simulation >> Solve and
Animate from the main menu or click the Solve and Animate button 
on the Run Mode toolbar.
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How
can I simulate varying quantities? Can I store the results?
You can simulate varying
quantities (and store the results) by using the Time Step
Simulation (TSS) tool. TSS allows you to specify
operating conditions and obtain power flow solutions for a set of points
in time. It provides the tools needed to analyze the operation of
a power system hour by hour. TSS
is included in the base Simulator package. OPF and SCOPF
licensees can also solve hourly optimized scenarios in which the
TSS tool obtains the optimized generation dispatch for each hour
of the analysis horizon. Click
here to view a demonstration of
a Time Step Simulation. See the Time Step Simulation chapter
in the help files included with your software for more information on
how to use the TSS tool and store the simulation results.
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Can I have negative marginal prices? What do they mean?
Yes,
in highly congested systems you can in fact see negative LMP's at a bus
(or buses). This is always coupled with high LMP's at other buses.
A negative LMP means that serving an additional MW of load at
the negative LMP bus will reduce the operating cost. More flow to the
load creates a counter-flow that tends to mitigate congestion in an
element. This allows for dispatch of cheaper generation, thereby
decreasing the overall operating cost.
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I am
getting $5000 / MW-hr LMP's. Can that be correct?
If a constraint cannot be enforced due to insufficient
controls, the slack variable associated with enforcing that
constraint cannot be
removed from the LP basis. Marginal cost depends on the arbitrary cost of the slack
variable. This value defaults to $5000 per MW-hr in
order to enforce the equality constraint that a control area’s
generation should be equal to the area demand plus the area
losses, plus the area scheduled interchange.
The value is specified in the Marginal
Violation Cost field of the LP
OPF >> Options dialog. See the
following topics in the help files included with your software for
more information:
- PowerWorld Simulator Add-on
Tools >> OPF >> Options
- PowerWorld Simulator Add-on
Tools >> OPF >> Examples
- Tutorials >> OPF
>> Marginal Cost of Enforcing Constraints
- Tutorials >> OPF
>> Unenforceable Constraints
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What
method does the OPF/SCOPF solution use?
It is a sequential linear
programming optimal power flow. We use our own revised simplex
code.
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What contingencies should I include?
This is more of a consulting-type question than a technical support
question; there is no industry-wide rule of thumb in this matter.
Typically, a user's list of contingencies is dictated by:
-
The size of the network
being simulated
-
The information the user
is trying to obtain by performing the simulation
-
The network proximity of
possible contingent system elements to the portion of the system
being studied. For example, when performing an analysis to
determine the feasibility of installing a new transmission line in
New England, an engineering decision must be made to include or not
include possible contingent elements in Florida
Generally,
the engineer performing the simulation should be consistent in the
choice of contingent elements and must be able to defend his or her
system model.
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What
formats can Simulator read?
Simulator
can read-in
publicly available text file formats such as .RAW and .EPC. Our
software is read
and write compatible with PTI Versions 23
thru
30
and GE PSLF Version 11.1.
Simulator
also supports
(reading in of) one-line
diagrams in PTI DRW file format.
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Can
I solve a Real-Time power flow in Retriever?
Yes. The data that is
imported from the real-time sources can be substituted for the
underlying system data to solve a real-time power flow in Retriever,
provided that:
-
a complete system model
with all required object fields necessary to run a power flow
solution is provided (see case validation), and
-
the underlying model
fields (when combined with the imported real-time data) are well
conditioned for a solution
Although Retriever does not
require a system model capable of being solved in order for it to
perform its function of importing and displaying real-time data, it
comes standard with both Edit and Run modes (in addition to Real-Time
mode). Edit mode allows the user to edit the underlying model
parameters and to develop and make changes to system diagrams. Run
Mode allows for system simulation and power flow analysis. When
a case is first opened in Retriever, the software automatically
validates the case. Case validation does not guarantee that a
system will solve, but it does check to ensure that all required power
system elements are present to attempt a solution.
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What does SImulator/Retriever
check when validating a case?
Validation checks for both
errors that would prevent a case from working properly and
for abnormal setup of model objects. Validation errors and warnings are
displayed in the Message Log. A sampling
of the tasks performed during case validation include:
-
Ensures there is a
system slack bus assigned
-
Ensures the slack bus
has an attached generator
-
Ensures that no
generator is assigned to remotely regulate the slack bus
-
Checks for buses having
multiple controllable devices attached (i.e. switched shunts)
-
Checks all max/min
enterable fields to ensure that the max value is greater than the
min value
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