 This work gives a comprehensive overview of the
achievements in the field of modeling and active control of instabilities in compressions
systems during the last decade.
Existing models of unstable compression systems are in most cases
restricted to constant speed compressors. Here, two models are derived that take time
varying rotational speed into account - one for centrifugal compressors and one for axial
compressors.
- The main focus of the modeling element is the inclusion of non-constant speed in
existing dynamic models of unstable compression systems, and the study of surge and
rotating stall in connection with this.
- The focus of the control element is the use of a close coupled valve as a means of
stabilizing surge and rotating stall. Little work has yet been published on this.
Using techniques such as backstepping and passivity, controllers for a
close coupled valve in the compression system are derived in order to stabilize the
compressors and extend the range of mass flows over which it can be operated stably.
Detailed analysis of the closed loop systems is performed, and many case studies with
simulations are presented.
Scientists and graduate students working in this area will find this
particularly useful. It will also be a valuable addition to libraries and the industry as
a whole.
Other publications from Jan Tommy Gravdahl:
- Gravdahl, J.T. and O. Egeland, Two
results on compressor surge control with disturbance rejection.
Proc. of the 37th IEEE Conference on Decition and Control, December 1998, Tampa Fl. Abstract:
This paper presents two results on design of compressor surge controllers with disturbance
rejection capabilities. First, constant disturbances are included in the Greitzer model,
and adaptive backstepping is employed to derive a surge control law for a close coupled
valve. Global asymptotic stability is proven. Then, time varying disturbances are studied.
A controller is derived using passivity, rendering the closed loop system L2-stable.
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