Nonlinear Predictive Control of a Hydropower System Model

Runfan Zhang,Diyi Chen,Xiaoyi Ma

doi:10.3390/e17096129

Abstract

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.

Highlights

Hydropower, as a low-cost, zero-pollution and renewable energy, has been developed since the twentieth century [1]
The numerical experiments of the nonlinear predictive control of the six-dimensional hydropower plant are presented in this part
Can the NMPC method stabilize the hydropower system introduced in this paper, but it can be applied in other systems described by state-space equations

Summary

Introduction

Hydropower, as a low-cost, zero-pollution and renewable energy, has been developed since the twentieth century [1]. Many hydropower plants with great capacity are being built around the world to generate electricity to resolve the serious energy problem. The system of such a powerful hydropower plant including penstock systems, water turbines, generators, regulators and loads, is so complex that it is difficult to control [2]. In [4], a new adjustment method of PID governors was proposed for hydropower plants with long penstocks to control the power frequency. A micro-hydro power plant model with a smaller, lighter, more robust and more efficient higher-speed turbine was built in [5], and a control scheme was proposed. In [8], a control method based on integrating the entropy and mean value of the tracking error with the constraints was proposed for hydro-turbine speed governors

Results

Discussion

Conclusion