See Also
This topic will get you started with using the Time Step Simulation tool and help you become familiar with the basics of setting up a time step simulation run.
The Time Step Simulation dialog is displayed when you access the Time Step Simulation by selecting Time Step Simulation from the Run Mode ribbon group on the Tools ribbon tab. This dialog contains several pages. The Summary page is used to define and control the time points you want to analyze. As an example, we will assume that you have hourly load data for tomorrow and that you want to determine the system bus voltages for each hour. You would do the following:
Step One: Set the List of Time Points
In order to create a list of points, right-click on the Summary page and select Insert New Timepoint(s), which brings up the New Timepoint Dialog. In this dialog, select tomorrow’s date from the drop down calendar component. Set the field Total Number of Timepoints to Enter to 24. Assume the other default values are acceptable and click OK. This will insert 24 time points, one for each hour starting tomorrow at 12:00 AM.
Step Two: Specify Input Data
Input data is specified on the Input Page. In this example your input data corresponds to hourly loads. Select the MW Loads sub-page. In order to specify hourly load values you have to insert a column for each load. Right-click on the grid and select Time Point Records > Insert/Scale Load Column(s) to bring up the Insert/Scale Column Dialog. In the selector component, select the load for which you want to specify hourly values. You can press the shift key to select multiple elements. Then press the blue Arrow Button to pass the selected loads to the right side of the selector. Select OK to insert the new column(s). Now you can specify the hourly MW values for those loads.
Step Three: Specify the Custom Results
Obtaining solutions for a large number of time points has the potential to create unnecessary burden in memory and storage due to the large amount of data that can be generated. For this reason, the Time Step Simulation tool allows you to explicitly specify what quantities you want to display and store. This is done on the Results page. This page contains grids for many devices including Generators, Lines, etc. In this example we want to analyze the bus voltage magnitudes. We specify what quantities we want to store as results for each object by clicking the View/Modify button, which brings up the Custom Results Selection Dialog. In this dialog select the Buses page and click the Add/Remove Fields button to bring up the list of Available Bus Fields. Find the Per Unit Voltage field and Add this to the list of Selected Fieldsand then click OK when done modifying fields. Results will be saved only for those buses that have the Time Selected field on the grid set to YES. Set this field to YES for the buses that you want to save. Click the Save and Close button to save the custom results settings, i.e., which objects, fields and records are to be kept during the solution; in this case bus voltages.
Step Four: Run the Simulation
The upper part of the Time Step Simulation dialog contains buttons used to control the simulation. To do a full run of the 24 hours click the Do Run button. The Last Result box shows the progress of the simulation as each time point is being solved. If you are in the Results – Buses page, you will see that a column was added for each bus set to YES in the Custom Results Selection Dialog. Each column shows the bus per unit voltage. Recall that you can right-click on any Simulator grid and select Plot Column to obtain a plot of the column values. If you select cells spanning all the bus per unit voltage columns, you will obtain the voltage profiles for each bus, versus time.
If you are in the Summary page, the Processed column shows that each point was in fact processed and solved.
Step Five: Save the Results
Once you have completed the simulation, you can save the results in a Time Series Binary (.tsb) file by pressing the Save TSB File button. This file will contain all the input data, the simulation options, the custom results settings, and the results. You can reload this .tsb file any time by pressing the Read TSB File button.