How to find Thevenin Impedance at Bus 1 in a Two-Area System with Synchronous Machines?

I am trying to determine the Thevenin impedance at Bus 1 in a simple two-area power system. I attempted to calculate it using the ratio of open-circuit voltage to short-circuit current from two separate simulations. However, the result does not match the manually calculated Thevenin impedance.

Is there a recommended or more accurate method to obtain the Thevenin impedance in such a system?

Also, is it possible to use the Impedance Measurement Tool in Simulink to find Thevenin Impedance for a network that includes synchronous machines? If so, are there any specific considerations or limitations I should be aware of?

Any guidance or suggestions would be greatly appreciated.

Answer 1

[Sabin]

Is it possible use the Impedance Measurement Tool. The Impedance Measurement Tool can be used in networks containing synchronous machines; however, you should ensure the machines are in steady-state and that their controllers (such as AVR or governors) do not interfere with the test signal.

Alternatively you can explore the approach using Simulink Control Design and Simscape, see this example for a starting point:

https://www.mathworks.com/help/slcontrol/ug/measure-boost-converter-impedance-using-signal-generator-blocks.html

[DS]

Thank you very much for your response. Would setting the AVR gain (Ka) and governor droop (R) to zero be sufficient to eliminate their influence, or are there any additional changes required to ensure they don't interfere?