Nonlinear Modeling of Compression System and Stability with Recirculation (Dept.M)

The model of compression system is used for capturing the dynamics of rotating stall and surge. In this paper, we introduce the modeling formulations of compression system after modifying the original work proposed by Moore and Greitzer (1986). Recirculation technique is used to eliminate the instabilities of compression system, where bled air from downstream compressor via bleed valves is re-circulated to injectors upstream of compressor inlet. The form of the modeling takes the four-state low order model which applied to design the 110nlinear controller. The compressor works in stable regime by using recirculation technique. Lyapunov Control Function (LCF) is used to produce optimal control to stabilize the compressor operation by using recirculation technique, whereas simulation results show that it is a good technique. By using recirculation technique bleed valves requirements are reduced.  Keywords: Compression system, Compression system modeling with re-circulation, Surge control