See Also
On the various option dialogs for devices such as Generators, Load, Switched Shunts, DC Lines, and Transmission Lines, there will be a tab labeled Stability. On this tab you will be able to define the appropriate dynamic models for the device. An example of the generator dialog's Stability tab is shown as below.
All of these tabs have a similar layout which includes the following attributes
Insert Button
Clicking this button to insert a new model. A dialog will appear prompting you to choose which specific type of dynamic model to add for the object.
Delete Button
Clicking this button to delete a model.
Type Drop-Down
Shows a list of the presently defined models for this class. A model which is active will say Active before giving the name of the model. Normally there will only be one model of each class, but Simulator does permit you to define multiple models. For some models only one can be active at a time.
Active Check-box
There will be a check-box to make a dynamic model Active or Not Active. When a model is not active then it will be included in the dynamic simulation. Also note that for some classes of models you can have only one active model at a time. Governors, Exciters, Machine Models, and Stabilizers for generators all behave this way, however if you're defining a relay model you may have more than one active.
Show Block Diagram Button
When clicking this button, the BlockDiagrams.pdf Adobe Acrobat file will automatically be opened which contains all the dynamic model block diagrams. This PDF file will automatically be navigated to show the block diagram of the presently model.
Parameter List
At the bottom of the tab is a panel with numerical edit boxes allowing you to define all the input parameter values for the model. Next to each edit box is the name of the parameter. In addition to this if you hover the mouse over the edit box a hint will appear with a more detailed description of the parameter. The edit box, the non-default parameters will be highlighted as bold.
Special Options only on the Generator Dialogs
Set to Default
On the generator dialog there are options to change the parameters to PowerWorld's default settings.
Option to enter values on either the Device MVA base or the System MVA base
Normally per unit values for stability data are entered on the MVA base of the device. If you would like to change to enter data on the System MVA base instead, change this option. (Note: this option only affects the dialog entries. Entries in the case information displays will always be on the device MVA base.)
Several Model Class Tabs
Generator dialogs will list sub-tabs for Machine Models, Exciters, Governors, Stabilizers, and Other Models. Each of these sub-tabs has the same layout.
Step-up Transformer Tab
Information about an assumed step-up transformer may also be included with the generator and can be entered here.
Terminal and State Tab
After the transient stability run has been initialized on the Transient Stability Dialog, you may go to the Terminal and State Tab to View information about the terminal values and dynamic states. Under this tab will be several more sub-tabs as follows
Bus/Setpoint Values: Shows voltage and current on the system MVA base at the terminal bus. Shows the MW, Mvar and MVA being injected into the system at the terminal bus as well. Also shows the Exciter Setpoint (Vref) and Governor Setpoint (Pref) values if appropriate.
Terminal Values: Shows the Terminal Voltage and Current on the device per unit base. Mechanical MW, Accelerating MW, and Terminal MW. Also shows information about the internal rotor angle, Frequency Deviation (omega), and acceleration. Also shows information about the Field Voltage and Current and the Direct and Quadrature axis terminal and internal voltages and currents
Several Model Class State Tabs: tabs for Machine Models, Exciters, Governors, and Stabilizers will be available. Each will contain a list of the present states for the model as well as the derivatives of each state. For the derivative values, the states are sometimes ignored (such as when a time constant is zero). If this is true for the model, the derivative will be listed as Ignored.
Create VCurve
Creates a curve of 50 points intervals of the Field Voltage and the Field Current of the generator in reciprocal and non-reciprocal values. To get the results it will used the current terminal of the bus and the minimum MW of the generator and it will vary the MVar of the generator from the minimum to the maximum MVar. It will repeat the same procedure with the present MW and the maximum MW of the generator.
Special Options only on the Load Dialog
Type Drop-Down Modification
Because for a load model, the model can be inherited from the bus, owner, zone, area or system, the model listed under the Type drop-down may not be associated directly with the Load object. If this is the case the model list will show the string Inherited. For inherited models you will not be able to edit the Parameter List directly. To edit the parameter list you will need to go to the dialog for that particular object in the Transient Stability portion of the Model Explorer.
Special Options only on the Branch Dialog for Line Relays
Show Relay Zones
Many line relays are impedance type relays which have a specified geometric circle, lens, tomato, or rectangular characteristic. For these relays there will be an extra button Show Relay Zones. Click on this button to display a mho circle plot showing the relay zones in the Apparent R-X plane. Note also that various points showing the location of the impedance of the actual branch, as well as the forward reach points and percentages will be shown.
Set Device ID
Many Relay model allow to have multiple relays at both ends of the branch. The Set Device ID will let you modify the DeviceID from the dialog for those line relays.
When you press the Set Device ID button the following message box will appear and there you could enter the new Device ID. It will only rename the Device ID if the new Device ID does not exists. If the Device ID already exists then the following message will appear: "A Device ID (ID) already exists at From/To end (Line Name). Please Modify that particular (Relay Name)relay."