Robust fixed-time sliding mode control for fractional-order nonlinear hydro-turbine governing system

Sunhua Huang, Bin Zhou, Siqi Bu, Canbing Li, Cong Zhang, Huaizhi Wang, Tao Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

26 Citations (Scopus)

Abstract

This paper proposes a nonlinear sliding mode controller for effective fixed-time stabilization of a hydro-turbine governing system (HTGS). The HTGS is a highly nonlinear, multi-variable coupled and non-minimum phase system to maintain frequency stability by regulating the generation output in response to load variations. The state trajectories of HTGS under random load disturbances exhibit unstable behaviours on the rotor angle, rotor speed, and guide vane opening, which would affect the stable operation of hydroelectric stations. In the proposed approach, the fractional calculus technique is adopted to model the nonlinear dynamics of fractional-order hydro-turbine governing system (FOHTGS). In order to validate the system stabilization and convergence within a bounded time, a robust sliding mode controller is proposed to force the FOHTGS to reach the equilibrium point based on the fixed-time stability and Lyapunov stability theories. The proposed controller can guarantee the superior stabilization of FOHTGS with the bounded and quantifiable convergence time, and thus overcome the drawback of finite-time controllers whose convergence characteristics are heavily dependent on the initial conditions. Finally, numerical simulations have been implemented to confirm the effectiveness and superior performance of the fixed-time controller compared with the existing finite-time control methods.

Original languageEnglish
Pages (from-to)447-458
Number of pages12
JournalRenewable Energy
Volume139
DOIs
Publication statusPublished - Aug 2019

Keywords

  • Fixed-time stability
  • Fractional-order modelling
  • Hydraulic energy
  • Hydro turbine
  • Renewable energy

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment

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