Surge control and test functions for axial flow compressors

The focus of this paper is bifurcation control for axial flow engine compressors. The Moore-Greitzer model is adopted for the analysis. We introduce test functions whose zeros are critical to Hopf bifurcation for the closed-loop system where nonlinear feedback control laws are employed. A test function is also developed to determine the stability of the periodic solutions born at Hopf bifurcation. The analysis based on these test functions leads to a new method of feedback design for control of both stationary and Hopf bifurcation in axial flow compressors. Using the techniques proposed, feedback controllers can be designed to meet several bifurcation control requirements, including elimination of the behavior of surge, coupled with rotating stall