Robust controller design for a three-shaft industrial gas turbine in the infinite grid power generation

Abstract

Due to the sensitivity of gas turbines’ power generation in Iran, robustness is considered as a crucial matter and the controllers play an essential role in this objective. The common controllers used in gas turbines are usually based on standard performance. Whereas, robust controllers demonstrate acceptable performance in the presence of adverse factors such as uncertainties, disturbances, and input step changes. In this study, dynamic structures and various robust control design scenarios for an MGT-30 three-shaft gas turbine have proposed. Input-output matrices have been presented based on the dynamic model structures, and a standard robust controller structure has been used to design and present transfer matrices. Four scenarios have been considered in the robust control design according to the number of control variables, uncertainties, and disturbance effects, evolutionally, respectively. $H_{\infty }$ and $H_2/H_{\infty }$ methods were used in the controller design when presenting the results of using the existing PID controller. The results show that with the increase and develop in parameters influencing the production of the actual system behavior and the controller responses improve noticeably. Finally, the fourth scenario was proposed as a scenario with more desirable robustness features than other scenarios, which provide a complete array of robust controllers.