The AC voltage source can be controlled in RMS simulation by applying different input values to signal sets (u0,f0) or (U0,F0Hz). The first set controls the per unit quantities, the second absolute ones. Two solutions are available:

1. applying parameter events (EvtParam) directly to the Voltage Source on these signals. This way, step wise changes in the voltage magnitude and frequency can be introduced.

2. creating a DSL model that will control the signals of the Voltage Source. This method allows any type of input signal variation (not only step events).

An example for method 2 is attached below. The DSL model receives signal references from an external text file for the variable set (u0,f0). In the example, the text file contains data formatted as below:

Column 1 [tab] Column 2 [tab] Column 3

time [tab] voltage magnitude [tab] voltage frequency

Usage instructions:

- Save the attached files to your computer

- Import in PowerFactory the example project.

- Identify the External "Measurement File" (ElmFile) using either the Data Manager or the Model Manager. Open its edit dialog and update the Filename field accordingly such that the path points to the actual location on your computer. Click OK afterwards.

- Run an RMS simulation and observe the voltage and frequency in the plot "Results". Edit the text file and make further modifications as you find suitable.