In: Electrical Engineering
Consider the transfer function G(s) = 1/[(s+1)^2(s+2)]. We use a PI compensator C(s)=(as+b)/s and close the feedback loop.
1.) Find out the entire range of a and b at which the closed-loop is stable and show it on the plane with a and b axes.
2.) At the border of instability, find the frequency of oscillations in terms of a.
3.) For what value of a, do we get the largest range of b for stability? What is this largest range?