Transient Stability Analysis Options: Valid Remedial Actions Fields

 

Many more fields are available for inclusion in steady-state remedial action definition and criteria monitoring than are available for transient stability. The Show Valid Remedial Action Fields button on the Remedial Actions tab of the Transient Stability dialog will provide the most up-to-date list of the fields and object types for which they are supported.

 

The resulting list of fields supported in transient stability will contain the following information:

Object Type

Name of object type for which the field is supported.

Variable Name

Variable name of the field that is supported.

Allow Derivative

This will be YES if the time derivative of the field can be calculated when it is used as part of a Model Expression.

Always Every Time Step

When this field is YES the user has no input on whether or not this field will be evaluated every time step. Fields where this is imposed are Status, Online, DerivedStatus, and DerivedOnline. When this field is NO the user must specify if this field should be evaluated every transient time step. If a field is not evaluated every time step it is evaluated in the initial state for a transient stability run and this value remains constant for every time step.

 

 

 

To specify that a field be evaluated every transient time step, there are options with Model Conditions and Model Expressions.

On the Model Condition dialog the Eval Trans Time checkbox will be enabled if a field is selected that is supported for being evaluated every transient time step and the field is not forced to be evaluated every time step, i.e., Status, Online, DerivedStatus, and DerivedOnline:

 

 

 

On the Model Expression dialog each expression variable has an EvalTrans option to specify whether or not it should be evaluated every time step. This option will only be enabled for fields that are supported for evaluation every transient time step and not forced to be evaluated every time step, i.e., Status, Online, DerivedStatus, and DerivedOnline:

 

 

When defining Model Conditions and Model Expressions and using the Choose a Field dialog to select fields, checking the Show Transient Stability Remedial Action Fieldscheckbox will limit the list of fields shown in the chooser to only those that are supported for being evaluated every transient time step: