Efficiency Improvement of Nonlinear Compressor System with Robust MIMO Reset Approach

Abstract

In this study, a control design of the compressor system is analysed in order to demonstrate its characteristics and to improve efficiency. The state space model is constructed by the Moore-Greitzer nonlinear equations. Upstream flow acts as a control loop disorder and the compressor system cannot meet the requirements with flow variance, so it is essential that the controller adapts to the new conditions. Because the control signal is connected to the system output by a nonlinear model, a reset controller is used to control the compressor system. A robust reset controller has designed consistent with the PI + CI method. The robust controller is designed as multi-input-multi-output and uses two throttle control valve and close-coupled valve actuators to apply control signals. Two reset controllers with a harmonious combination in the structure of the compressor system provide the possibility of following the desired pressure and flow states. The proposed controller can stabilize the compressor and increase its efficiency in the event of any disturbance in addition to preventing surge instability. The simulation results show that the reset controller can provide good performance. It is proved that the convergence rate changes with changes in the controller parameters. Finally, the stability of the controller is examined under the most severe conditions.