Stability and Control Analysis of Centrifugal Compressor

Compressor stall and surge are complex nonlinear instabilities that reduce the performance and can cause failure of the system. The emphasis has been on gaining a better insight to stalysurge dynamics and to predict their occurrence and controlling. This report presents a bifurcation-based analysis of the dynamical behavior and control of stall and surge in centrifugal compressor stage using MG86 model. This analysis gives compressor instabilities and provides a complete picture of the flow behavior at different operating points. A proposed nonlinear control law by Gu [9] along with the effect of rotational disturbances has been studied using this method. Using this control law it was shown that, abrupt entry of compressor into rotating stall can be avoided, eliminating the hysteresis between entry into and recovery from the rotating stall. Through analysis it was shown that system maintains stability up to a certain value of compressor rotational speed