I'm working on a problem that involves a Ćuk converter. The question asks "find k_c (a gain for a controller) such that the system is marginally stable".
So I got the properly space-state model with matrices A and B. Then, I set the real part of the eigenvalues of A equal to zero and try to solve for the unknown k_c. After that I got that kc must be equal to -1.8 approximately. That is, a negative gain.
- Is it physically feasible to implement in real life?
- Does it make a difference to use a positive gain or a negative gain?