MATLAB: Undefined function or variable “xa” error message

gui simulink block

Hi. As part of my research work, I am investigating the synchronous machine stability at low speeds. I connected the SI fundamental simulink blockset machine with exciter and speed input to a load. Before I simulating I have tried to carry out a load flow to get steady state using the powergui with no success! I keep getting the error, Undefined function or variable "xa" in the matlab window. Unfortunately I cant get past this error and its delaying my research considerably. Can anyone give me direction on this please…..Thanks.

Best Answer

  • In the Simulink model, press Ctrl+F, search where the variable 'xa' is used. Then assign a proper value to 'xa' in MATLAB Command Window, for example: