Experimental Evaluation of a High-Gain Control for Compressor Surge Suppression

The present paper considers the suppression of surge instability in compression systems by means of active control strategies based on a high-gain approach. A proper sensor-actuator pair and a proportional controller are selected that, in theory, guarantee system stabilization in any operating condition for a sufficiently high value of the gain. Furthermore, an adaptive control strategy is introduced that allows the system automatically to detect a suitable value of the gain needed for stabilization, without requiring any knowledge of the compressor and plant characteristics. The control device is employed to suppress surge in an industrial compression system based on a four-stage centrifugal blower. An extensive experimental investigation has been performed in order to test the control effectiveness in various operating points on the stalled branch of the compressor characteristic and at different compressor speeds. On one hand, the experimental results confirm the good performance of the proposed control strategy; on the other, they show some inherent difficulties in stabilizing the system at high compressor speeds due to the measurement disturbances and to the limited operation speed of the actuator.