Theoretical and Experimental Investigations on the Stability of Switched Heavy-Duty Gas Turbine Control Systems

Abstract

The heavy-duty gas turbine control system consists of multiple control loops and commonly switches among different control loops as operation conditions change. Due to the switching behavior, the stability of each loop does not guarantee the stability of the entire system. Therefore, it is of great significance to investigate the stability of switched heavy-duty gas turbine control systems. In this article, the switching stability between two representative control loops is investigated. First, the modified Rowen model of a 275 MW single-shaft heavy-duty gas turbine is introduced based on the operating data. Then, the discrete-time model of the switching dual control loops is developed. On this basis, a norm-based necessary and sufficient stability criterion is derived. The result is further extended to the case with time-varying delays under a unified switching system framework. Finally, an experimental platform is developed for the efficient and cost-effective evaluation of the heavy-duty gas turbine control systems. Some experiments are also carried out for analysis and verification.