Issues related to recovery from the occurrence of rotating stall in axial-flow-compressor dynamics are presented. Though Liaw and Abed (1996) proposed a bifurcation control law to prevent abrupt change of pressure increase due to the appearance of the so-called `rotating stall,' such a design might only be effective in a local sense. For large disturbances or high-speed operation, a compression system still can become unstable. Instead of providing high pressure increase with a small magnitude of stall wave as proposed by Liaw and Abed (1996), in this paper, a fuzzy rule is proposed to clear the stall cell and push the compressor dynamics to the desired high pressure increase unstalled operating point. Based on a lumped parameter model proposed by Moore and Greitzer (1986), the magnitude of the stall wave is shown to strictly decrease if the magnitude of the mass flux is higher than its value associated with the so-called `stall inception point.' The stall wave is then proven to be efficiently damped out by increasing the magnitude of the mass flux via dynamic setting of the throttle. A set of fuzzy rules is constructed to perform the required task. Moreover, a subset of fuzzy rules is used to push the compressor dynamics to the desired operating point. In this design, only pressure increase and mass flux are required for constructing the control law. This facilitates implementation in real applicatication.
|Number of pages||11|
|Journal||Journal of Control Systems and Technology|
|State||Published - 1 Dec 1998|