Adirak Kanchanaharuthai

1. 1.1. The stability of modern electric power systems is increasingly challenged by growing load demands, constrained transmission infrastructure, and the integration of renewable energy sources t...

This paper proposes a novel filter-free recursive gain controller (RGC) for frequency regulation in nonlinear hydraulic turbine regulating systems (HTRS). The controller systematically constructs a nonlinear feedback law that ensures all closed-loop signals converge exponentially to user-defined bounded regions. Stability is rigorously proven using Lyapunov analysis, avoiding the ‘‘complexity explosion’’ problem inherent in conventional backstepping methods. Unlike dynamic surface control (DSC) or command-filtered backstepping control (CFBC), the proposed approach does not require any filtering mechanisms, simplifying implementation. Instead, it uses fictitious signals to estimate virtual controls, resulting in a simple structure governed solely by tunable gains. Comprehensive simulations under severe fault conditions demonstrate that the filter-free RGC achieves robust frequency stability with superior transient performance—faster settling times, reduced overshoot, and enhanced damping—compared to standard backstepping, DSC, CFBC, and synergetic control.

This study introduces a simplified adaptive backstepping excitation control aimed at improving the transient stability of electric power systems. The controller addresses the challenges of simplifying adaptive backstepping control for multi‐machine systems. Unlike traditional backstepping, dynamic surface, and command‐filtered backstepping controllers, ours eliminates the need for virtual stabilizing functions, their derivatives, and any filters, thus significantly reducing computational burden. Additionally, a one‐order compensation subsystem is employed to mitigate the impact of nonlinear uncertainties using an adaptive control scheme and the congelation of variables technique. Through this approach, the proposed controller involves only one actual control law and one adaptive law, allowing for direct use. The performance of the closed‐loop system is analyzed based on the Lyapunov stability theorem. The effectiveness of the proposed method is evaluated using an IEEE 9‐bus multi‐machine power system (WSCC power system) consisting of nine buses and three machines. Simulation results demonstrate the efficacy of the developed controller and its superior performance compared to traditional backstepping, dynamic surface, and command‐filtered backstepping control designs.

This paper focuses on the nonlinear asymptotic tracking control for a hydraulic turbine regulating system (HTRS). The proposed control approach combines a recursive gain control scheme with an adaptive technique to achieve asymptotic tracking. An important characteristic feature of the proposed controller is the incorporation of a smooth function with a time‐varying function that is integrable and positive. This function provides the developed controller with sufficient power to achieve asymptotic tracking, whereas the recursive gain control alone can ensure that tracking errors converge exponentially to zero within balls of any arbitrarily small radii. The simulation results demonstrate the efficacy of the presented control technique, which outperforms backstepping, command‐filtered backstepping, dynamic surface, synergetic control designs; deals with the “explosion of complexity” problem; and simultaneously achieves asymptotic tracking. Furthermore, even though the HTRS parameters vary, the proposed technique is capable of providing consistent control performance. As a result, the presented controller is unaffected by changes in the system's parameters.

This paper proposes a nonlinear controller strategy for the frequency regulation of a hydraulic turbine regulating system (HTRS). An immersion and invariance (I&I) technique is utilized to develop the desired control law. The derived control method is used to guarantee that the equilibrium point is asymptotically stable. Furthermore, it can ensure that all overall closed-loop system trajectories are bounded. The feasibility and effectiveness of the technique are demonstrated using a nonlinear dynamical system of an HTRS connected to a single-machine infinite bus (SMIB) power system. The simulation results demonstrate that the technique is capable of regulating the frequency and improving dynamic performance despite large disturbances. It is capable of rapidly reducing oscillations and surpasses two known nonlinear controllers, namely the synergetic control and the backstepping control techniques. Additionally, despite the fact that the HTRS's parameters vary, the proposed technique is capable of providing consistent control performance. As a result, the presented controller is insensitive to variations in the system's parameters.