Effects of actuator limits on active control of rotating stall and surge

Yong Wang, CDS, Caltech

Operability enhancement is one of the major goals in active control of rotating stall and surge in axial compressors. But the achievable operability enhancement is serious limited by the magnitude and rate saturation limits of the actuators. In this talk, we analyze the effects of bleed valve actuator limits and system noise based on the three state Moore Greitzer model using the technique of center manifold and normal form reduction. We setup an optimal control problem which turns out to be a minimax problem. The optimal controller is solved based on the reduced systems. For the pure stall case, analytical formulas have derived by approximation of the stable manifold of the saddle for the reduced system. These formulas have shown good qualitative agreement with experiments and simulations to a high fidelity model. The technique can be generalized to dynamical systems with a simple Hopf bifurcation with controller entering the bifurcation parameter.