Warning 112 | [PSS®E] | SMIB fault not on Thévenin source branch

Relevant software:

PSS®E

Emitted message:

SIMPLEFAULT: Neither end of the specified LINE= arg is the infinite bus
VDISTURBANCE: Neither end of the specified LINE= arg is the infinite bus

Description:

This warning indicates that neither end of the line specified in the LINE= argument of a SIMPLEFAULT or VDISTURBANCE command is connected to the Thévenin source (infinite bus).

Possible impact:

• This configuration may lead to voltage profiles that differ from what was specified in:
  • The SIMPLEFAULT command's FZ= argument or;
  • The VDISTURBANCE command's VPU= or VCHANGEPU= arguments.
• This can cause this power system result to not benchmark with other power system results (unless they have an identical additional impedance in series with the Thévenin source)

Potential fixes:

• Review your PSS®E model to confirm there is a single line connecting the Thévenin voltage source's bus to the point of connection of your generating system.
  • If there are additional lines:
    • Check the line in the SIMPLEFAULT, LINE= argument is the same line as the one which defines the Thévenin equivalent resistance in your PSS®E model.
    • Consider removing additional lines or setting those lines to near-zero impedance (R=0 and X=0.0001 per unit) in order to not cause error in the SIMPLEFAULT, FZ= calculation.
  • If there are additional lines and their impedance is set to be negligible, this warning can be ignored (though removing the additional lines is still recommended).