See Also
During a Time Step Simulation run, special control actions can be implemented for transformers and switched shunts. These control actions allow time delays to be used so that a specified period of time passes, while a device is outside of its regulation range, before that device can implement a control change that will attempt to bring the device back within its regulation range. Multiple transformers and switched shunts can be on this type of control.
In addition to transformers and switched shunts that allow switching time delays during a time step simulation run, there are special Time Step Actions that can be utilized during a time step simulation run. Time Step Actions perform some action (e.g. opening a branch, moving load, changing generator output, etc.) once a specified Model Criteria evaluates to true and remains true for the specified time delay.
Time delays will only be used in a time step simulation if doing a complete time step simulation run. A complete run is one that is started using the Do Run button on the Time Step Simulation dialog and is allowed to run to completion without running any time steps out of order or repeating time steps. If not doing a complete time step simulation run, any transformers and switched shunts that model time delays will ignore the time delay settings and operate based on all other relevant control settings and Time Step Actions will be ignored.
When doing a complete time step simulation run, application of time delays fits into the time step simulation process in the following manner:
- Start the time step simulation by clicking the Do Run button on the Time Step Simulation dialog
- Initialize time delay objects and check for data errors
- If any data errors result, provide user option to continue with Simulator fixing the errors or abort the run so that the user can fix the errors
- Transformers and switched shunts that are modeling switching delays are turned off automatic control so that they will not move during the power flow solutions
- Process a time point
- If applying pre-script command before applying input data, run pre-script command
- If Apply Input Data
- Update loads, MW and Mvar
- Update generators, MW and Max MW
- Update line statuses
- Update area loads, MW and Mvar
- Update zone loads, MW and Mvar
- Update injection group injections
- Apply custom inputs
- If Apply Schedule Data
- Apply schedule actions
- If Input Data and Schedule Data can be applied with no errors or not applying these at all
- If applying pre-script command after applying input data, run pre-script command
- If choosing to Apply and Solve
- Solve power flow
- If successful power flow solution
- If any objects modeling time delay, check for time delay implementation
- Transformers
- Switched Shunts
- Time Step Actions
- If any system changes, solve power flow
- If still successful power flow solution (time delay actions implemented and power flow solves or no time delay actions implemented)
- If Solution Type <> Single Solution, run unconstrained OPF, OPF, or SCOPF
- If Run Contingencies = YES, run contingency analysis
- If applying post-script command before storing results, run post-script command
- Store results
- If applying post-script command after storing results, run post-script command
- Continue processing time points until all completed
- Restore time delay objects to original control modes