Full-state Variables Control of a Grid-connected Pumped Storage Power Plant Using Non-linear Controllers

Abstract

—In this article, a controller based on a multi-variable sliding mode is provided for pumped storage with four goals. (1) Full-state variables of the plant, generator, and hydro turbine are developed to improve transient responses under fault conditions by compensating the fast electrical dynamics. (2) The sliding-mode controller is designed for robustness against uncertainty in both the power system parameters and its topology. (3) Two surfaces (power angle and output voltage) are proposed to coordinate both the turbine and excitation inputs of the generator in transient conditions. (4) The decentralized method is used to decrease the complexity of the controller equations and cost of implementation. To show the effectiveness of the proposed controller, two other controllers—full-state variables feedback linearization and a generic power system stabilizer—are simulated by MATLAB/Simpower (The MathWorks, Natick, Massachusetts, USA). The simulation results show full-state variables feedback linearization cannot be robust against model uncertainty; it is also shown that the power plant with linear controller has unpleasant transient responses in both fault conditions and low-frequency oscillations. In contrast, the proposed method plays an effective role in solving the mentioned problems and limits the stator current magnitude and terminal voltage post-fault.