A novel combined approach for gas compressors surge suppression based on robust adaptive control and backstepping

Nowadays, there is a great interest in using active control methods to increase the compressor working range. The advantage of this controlling method is that the performance point can be located in the vicinity of maximum pressure and efficiency. However, most of the existing controllers require an awareness of compressor characteristic, disturbance upper bound, throttle gain, and throttle valve feature; this is why they are limited in engineering applications. In order to overcome the weakness of the existing controllers, this research employs a novel combined controlling method based on robust adaptive control, which is designed using backstepping technique because the compressor behavior is nonlinear. The increased efficiency and improved operational area for the compressor are provided by this controller without requiring any knowledge or information regarding the compressor characteristic, disturbance upper bound, throttle gain, and throttle valve feature. The adaptive controller has been used to compensate for uncertainties of the compressor characteristic and throttle valve as well as the un-modeled dynamics. Also, the controller robustness is a barrier against the time-varying disturbances in flow and pressure applied to the system. Finally, simulation results showed that the designed controller, in addition to assure the system stability, developed the compressor working range, and the convergence of system states was achieved after applying disturbance in flow and pressure.