Speed and surge control for a low order centrifugal compressor model

Previous work on stabilization of compressor surge is extended to include control of the angular velocity of the compressor. First, a low order centrifugal compressor model is presented where the states are mass flow, pressure rise and rotational speed of the spool. Energy transfer considerations are used to develop a compressor characteristic. In order to stabilize equilibriums 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 speed are derived. Semi-global exponential stability is proved using a Lyapunov argument