An Integrated, Full-Range Surge Control/Rotating Stall Avoidance Compressor Control System

In this paper we present an integrated compressor control scheme capable of achieving simultaneous surge control and rotating stall avoidance over the full range of compressor operation. The approach adopted in this paper is based on a combination of closed-loop feedback control and open-loop feedforward control of throttle valve area. The feedback control is based on a compressor mass fiow measurment. The feedforward control is based on measuremets of inlet and outlet pressure and temperature. Both the feedback and feedforward controller parameters are continuously scheduled as a function of nominal operating conditions. This approach achieves simultaneous surge control and rotating stall avoidance, over the full range of compressor operation, in the face of i) inlet and outlet pressure and temperature disturbances, and ii) variations in the demanded values of both compressor speed and mass flow. Alternative approaches involving plenum pressure feedback, widely reported in literature, are shown to posess inherent performance limitations not possessed by the mass flow feedback scheme presented here.