Centrifugal compressor surge and speed control

Previous work on stabilization of compressor surge is extended to include c ontrol of the angular velocity of the compressor. First a low-order centrif ugal compressor model is presented where the states are mass flow, pressure rise, and rotational speed of the spool, Energy transfer considerations ar e used to develop a compressor characteristic. In order to stabilize equili bria to the left of the surge line, a close coupled valve is used in series with the compressor. Controllers for the valve pressure drop and spool spe ed are derived. Semiglobal exponential stability is proved using a Lyapunov argument.