Eigenvalues stability related to system components ?

Eigenvalues stability related to system components? Hi, My system is VSI grid connected to the voltage and current controller in dq-frame. I found the eigenvalues of the system as clear in the picture. there are two positive values which mean the system is unstable but in the Simulink the system is stable, so that means I have some mistakes in the small signal model. How can I know which part of the system makes those two eigenvalues positive (unstable)??? Thanks in advance

[zhengbo huang]

Hello, I meet the same problem with you, unfortunately I haven't found the reason yet. My model has positive eigenvalues after linearization, which means that my model should be unstable, but the question is that Simulink can run the model successfully, and there is no error. Do you konw why the eigenvalues of the model can not reflect the stability of the model yet? Can you please tell me the reason? Thanks a lot.

[waell telmesani]

Hi,

Most probably you have a mistake in your mathimatical model. In Simulink, check the response of the system under different solvers (i.e, discrete(50e-6 s and 10e-6 s), continous) to make sure the response doesn't change.