Driving Point Impedances

See Also

 

Added in version 20

This tool is found on the Tools ribbon tab in the Other ribbon group under Connections > Driving Point Impedancesor in the Run Mode ribbon group under Sensitivities > Driving Point Impedances.

 

The driving point impedance for a bus is the impedance looking from that bus out into the system.

 

Model Type to Use

This determines the Ybus that is used for the calculations. The following options are available:

Transient Stability without Bus Local Shunts

Use the Ybus built from transient stability data. This includes the internal impedances of generators and loads (induction motors). Local impedances at buses including bus shunts, switched shunts, internal impedances of generators, internal impedances of induction motors, etc. are subtracted out of the Ybus for the bus for which the driving point impedance is being calculated. This is similar to what is done in the SMIB two bus equivalent calculations, and is the most appropriate option to choose.

Transient stability data should be loaded prior to running this calculation.

Transient Stability Including Bus Local Shunts

Use the Ybus built from transient stability data but do not subtract out any local shunt impedances as is done in the without Bus Local Shunts option.

Transient stability data should be loaded prior to running this calculation.

Power Flow

Use the Ybus built from power flow data only. This depends on the system slack bus and does not include the internal impedances of generators.

 

Calculate Driving Point Impedances

Click this button to implement the calculations. Any errors will appear in the Calculation Result box.

 

Results

The table at the bottom of the dialog will contain the Driving Point Impedance X and R values as well as Mag(nitude) and Degrees at each bus in the case.