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Impedance Scan

The Impdance Scan page allows the user to perform impedance scan with external third party software. Currently, only PSCAD is supported. And we are busy with implementing MATLAB support. Please contact us if you need the support for other software.

Figure 1: SISA impedance scan page.

F-Scan

Please provide the input data for frequency-domain related parameters. The Number of Frequency Points tells SISA how many frequencies between Start Frequency and End Frequency should be generated, while Scale specifies the style of the frequency step.

The perturbation signal can be defined by Perturbation Up [kV] for voltage or Perturbation Ip [kA] for current.

Simulation

It instructs how an external third-party software should run the time-domain simulation. For EMT simulations, the system in the simulation starts from zero and gradually establishes a steady state, after which EMT events (e.g., closing a circuit breaker) can occur. For many rounds of simulation based on the same system, running every simulation from zero is a massive waste of time. Instead, we can let the first simulation run from zero to a steady state and stop. The system's status at the stop moment is called a snapshot. All the remaining simulation rounds start directly from the snapshot instead of zero.

PSCAD

The user can provide input data specifically related to PSCAD software. Only the PSCAD Version of PSCAD 4.6.3 (x64) is currently supported.

The Working Folder must contain these files:

. A workspace file .pswx. The file name (without file extension .pswx) should be entered in the Workspace Name field. . A project file .pscx. The file name (without file extension .pscx) should be entered in the Project Name field. . The two library files MyLib.pslx and Toolbox.pslx can download for free on our website.

The user can use the Choose Folder button to enter the full path.

Figure 2: PSCAD folder.

You need to add an instance of the toolbox from the library file to your project file at a place in PSCAD based on your needs. Then PSCAD will automatically assign a component ID for this toolbox, and you need to provide the ID to the Toolbox ID field.

Run and Stop

After providing the input data, the user can click the Run button to start. The following steps will happen automatically:

  • Launch a new instance of PSCAD. Note that PSCAD 4 does not allow an already-launched PSCAD instance to be connected.
  • Create a snapshot.
  • Run a steady-state simulation to have a reference status.
  • Run through all frequencies described by the user with the perturbation signal.
  • Perform FFT analysis and output results.

When the application is running, the Run button will be disabled and Stop button will be enabled. The user can click the Stop button to terminate the simulation at any time.

Output

After the run is finished, SISA will create an output folder right in the Working Folder and put all the results there.

  • The file impedance.csv contains the impedances of all frequencies.
  • The file impedance.html visualizes the data stored in impedance.csv file in an interactive way powered by the open-source tool bokeh.

Figure 3: PSCAD output folder.

Figure 4: PSCAD output.

PSCAD Installation Path

When SISA tries to launch PSCAD, it first uses a common path that PSCAD 4 is installed on a computer. However, if your PSCAD is installed at a different path, please visit UserPage to let SISA know.

Figure 5: SISA user page.

PSCAD

There are different scenarios for the program folder naming convention:

  1. When the MyUpdater utility is used to install PSCAD, the program file format has that “…Testing” folder, as shown: C:\Program Files (x86)\PSCAD463 x64 Testing\bin\win64\Pscad.exe.

  2. When the InstallShield Wizard is used to install PSCAD on a new machine (no other PSCAD patches installed):

    • the default installation folder would be: C:\Program Files (x86)\PSCAD50\

    • the default application folder would be: C:\Program Files (x86)\PSCAD50\bin\

  3. When the InstallShield Wizard is used to install a higher patch of PSCAD 5.0.x (e.g. v5.0.2) on a machine that already has an earlier patch (e.g. v5.0.1), the installer will ask if you if you want to either:

    • Update the existing PSCAD 5.0.1 installation, then the same default folders as per Step 2 above would be used,

    • Or, perform a side-by-side installation of both patches, then

      • the default installation path for the new patch would be: C:\Program Files (x86)\PSCAD503\

      • the default application path for the new patch would be: C:\Program Files (x86)\PSCAD503\bin\win64

  4. When performing a silent installation, you can specify any installation folder via command line arguments.