Nonlinear Predictive Control of a Hydropower System Model

• Published in: Entropy (Basel, Switzerland) Vol. 17; no. 9; pp. 6129 - 6149
• Main Authors: Zhang, Runfan, Chen, Diyi, Ma, Xiaoyi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2015
• Subjects: control method; Control systems; Entropy; Hydroelectric power; hydropower system; Lyapunov function; Mathematical models; nonlinear predictive control; Nonlinearity; Penalty function; Predictive control; stability; Terminals
• ISSN: 1099-4300; 1099-4300
• DOI: 10.3390/e17096129

A six-dimensional nonlinear hydropower system controlled by a nonlinear predictive control method is presented in this paper. In terms of the nonlinear predictive control method; the performance index with terminal penalty function is selected. A simple method to find an appropriate terminal penalty function is introduced and its effectiveness is proved. The input-to-state-stability of the controlled system is proved by using the Lyapunov function. Subsequently a six-dimensional model of the hydropower system is presented in the paper. Different with other hydropower system models; the above model includes the hydro-turbine system; the penstock system; the generator system; and the hydraulic servo system accurately describing the operational process of a hydropower plant. Furthermore, the numerical experiments show that the six-dimensional nonlinear hydropower system controlled by the method is stable. In addition, the numerical experiment also illustrates that the nonlinear predictive control method enjoys great advantages over a traditional control method in nonlinear systems. Finally, a strategy to combine the nonlinear predictive control method with other methods is proposed to further facilitate the application of the nonlinear predictive control method into practice.