See Also
The Results Storage page is found on the Transient Stability Analysis dialog.
This section describes how to choose which results to store to RAM during the transient stability simulation. You may want to store results to RAM so that they can be viewed in the Transient Stability Results: Time Values. Be careful however because if too many results are stored you will run out of RAM causing the simulation to fail or generally slow down your computer. The Store to RAM Options mostly consist of a list of all the various objects in the model and a list of field which can be stored during the transient simulation. This is depicted in the figure below. Any information needed for a subplot's horizontal axis data is automatically stored to RAM.
Tables of Devices
Results for Generators, Buses, Loads, Switched Shunts, Branches, DC Lines, Multi-Terminal DC Records, Multi-Terminal DC Converters, Areas, Zones, Interfaces, and Injection Groups can be stored during the transient stability analysis. Each type of object has a list of transient stability related parameters that can be stored. Toggling the appropriate field to YES for an object will store that parameter for the selected object. Some objects such as generators also have dynamic models associated with them for which dynamic states can be stored. For these you will see columns for Machine States, Exciter States, Governor States, etc... which can be set to YES to store those states. Each object also has a Save All field. If this field is set to YES for a particular object, all transient stability related fields (except dynamic states) will be stored for that particular object without having to set all of the fields to YES for all of the parameters. For dynamic states you can not use the Save All field and must toggle the specific state field instead.
Also note that any values which are set to be part of a plot series in a plot definition will automatically be stored to RAM
All results are presently stored in memory. This means that a memory limitation could be reached is storing a large number of results.
Save Results for Open Devices
Check this box to save results for devices that are currently open. It is possible that a device that is currently open could be closed during the transient stability analysis so this device should not be excluded from the results.
Set All NO
Click the Set All NO button to reset all fields regarding RAM storage for the present tab being viewed to NO.
Set All NO for All Types
Click the Set All NO for All Types button to reset all fields regarding RAM storage to NO for all object types.
Set Save All by Type...
Click this bus to bring up a dialog containing check-boxes which allows you to choose which device types to toggle the Save All paramter to YES for. There will also be check-boxes regarding the various dynamic model state fields.
Plotting
Transient stability results are usually interpreted with the assistance of some sort of plot. There can be a large amount of data to sort through and options on this page as well as the Plots page are designed to assist in setting up meaningful plots. Plot Definitions must be created in order to view a plot. The plot buttons contained on the Results to Save page assist in creating Plot Definitions outside of the Plots page. See the Plots page for more detailed information about Plot Definitions and plot parameters. Once options on the Results to Save page are used to create plots, the plot definitions will show up on the Plots page.
In order to make a plot, objects and fields to include in the plot must be specified. How many objects and fields are selected will determine which of the following buttons are enabled and how the plot will be designed. To select objects and fields for a plot, simply select cells in the appropriate device table that include the fields and objects to show on a plot.
For example, to plot all generator rotor angles on a single plot, go to the Generators tab and select all of the records under the Rotor Angle field. After selecting the objects and fields, click the appropriate plot button, as described below, to create the plot definition.
As another example, to plot only the rotor angles and terminal MW value of only generators 1 and 2, go to the Generators tab. Move the MW Terminal field so that it is next to the Rotor Angle field. This can be done by using the Display/Column Options dialog or holding down the CTRL key and dragging a column to move it to a different place in the table. Select the records for generator 1 and 2 under both the Rotor Angle and MW Terminal fields. After selecting the objects and fields, click the appropriate plot button, as described below, to create the plot definition.
Make Plot
This button is enabled when at least one object record for a transient stability field is selected. This option will create a plot definition with a single subplot with all selected objects and fields appearing on the same axis group.
Make Plot Group by Field
This button is enabled when more than one transient stability field is selected. This option will create a plot definition with a single subplot with a separate axis group for each of the selected fields. All selected objects will appear on a given axis group.
Make Plot Group by Object
This button is enabled when more than one transient stability object is selected. This option will create a plot definition with a single subplot with a separate axis group for each of the selected objects. All selected fields will appear on a given axis group.