One-Sided Control of Surge in a Centrifugal Compressor System
Active surge control is studied in a centrifugal compressor system. To stabilize surge, a bleed valve is applied which is nominally closed and only opens to stabilize the system around the desired operating point. This bleed valve is controlled using a linear output feedback controller based on plenum pressure measurements. In this study, the practical limitations of this one-sided surge controller are examined. Experiments show that the performance of the controller is affected by measurement noise and the desired equilibrium point in the controller, which is not accurately known in the unstable operating region. Fully-developed surge is stabilized with relatively small stationary bleed valve mass flow using the proposed controller in combination with a small band-pass filter. Measurements are compared with the results of the Greitzer model. This model shows qualitative agreement with experiments. For the examined compressor system, a 3.5% extension of the stable operating region is obtained using the one-sided surge controller.