Smith Predictor Position Control for the Inlet Guide Vane of Centrifugal Air Compressors

Abstract

Fast and accurate positioning of Inlet Guide Vane (IGV) is critical for flow regulation in centrifugal air compressors, especially for surge avoidance control. Both transport delay and external disturbance are present for IGV position control on a compressed air system. A Smith Predictor based control scheme with the process-model modification is applied to this problem. The adopted control scheme can both compensate for the time delay and effectively reject step disturbances present in the IGV system. Simulation was conducted using simple PI controller and a PI controller with the Smith Predictor with process-model modification. It showed that the proposed control scheme can achieve zero steady-state error with the presence of external disturbance and the settling time was shortened. Robust stability and performance of the system was discussed.