Finite-time Takagi–Sugeno fuzzy controller design for hydraulic turbine governing systems with mechanical time delays

Abstract

The grid has increasingly higher reliability requirements for hydropower supply and regulation, imposing higher requirements for the stability of hydraulic turbine governing system (HTGS). The mechanical structure of the unit is complex, and the adjustment of the active guide vane needs the hydraulic servo system with multistage amplifier to provide force, which makes the governor response output lag. The control of an HTGS that focuses on Lyapunov asymptotic stability may have poor transient performance. Therefore, a brand-new nonlinear finite-time Takagi–Sugeno fuzzy control scheme for HTGSs with mechanical time delay is proposed. First, based on the Takagi–Sugeno fuzzy model with time delay, a time-delay HTGS that considers the inherent delay effect of the HTGS relay component as well as its fuzzy model is presented. Second, based on the finite-time stability theorem, a nonlinear finite-time Takagi–Sugeno fuzzy controller for the HTGS is proposed and a practical stability condition is given in the form of matrix inequalities. Furthermore, the matrix inequalities are transformed into a set of linear matrix inequalities, which are easy to solve. Finally, numerical experiments on HTGS under various operating conditions demonstrate the proposed scheme’s effectiveness and superiority compared with the traditional proportional integral derivative control.