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.