Dynamic control of axial compressors

Several control laws have been formulated by other authors to stabilize the low-order nonlinear state-space model of an axial compression system developed by Moore and Greitzer (1986). Using static nonlinear feedback, these control laws extend the stable operating range of the compressor system. This paper considers the merits of using dynamic feedback to implement the control law suggested by Sepulchre and Kokotovic (1996). Bifurcation and normal form analysis are used to show that the dynamic implementation of this control law is able to eliminate rotating stall by stabilizing a small axisymmetric limit cycle around the peak of the compressor characteristic. The analysis reveals the possibility that controlled dynamics can be used to create new and desirable phenomena.