(1990). ENERGY FUNCTION ANALYSIS FOR POWER SYSTEM STABILITY. Electric Machines & Power Systems: Vol. 18, No. 2, pp. 209-210.

Energy function analysis for power system stability

Model predictive control for optimal energy management of connected cluster of microgrids with net zero energy multi-greenhouses

This article presents a novel reconstructed model for the delayed load frequency control (LFC) schemes considering wind power, which aims to improve the computational efficiency for PID controllers while retaining their dynamic performance. Via fully exploiting system states influenced by time delays directly, this novel reconstructed method is proposed with a controller isolated. Hence, when the PID controllers are unknown, the stability criterion based on this model can resolve controller gains with less time consumed. For given PID gains, this model can be employed to establish criteria for stability analysis, which can realize the tradeoff between the calculation accuracy and efficiency. The case study is first based on a two-area traditional LFC system to validate the merits of a novel reconstructed model, including accurately estimating the influence of time delay on system frequency stability with increased computational capability. Then, under traditional and deregulated environments, case studies are carried out on the two-area and three-area schemes, respectively. Through the novel reconstructed model, the efficiency of obtaining controller parameters is highly improved while their robustness against the random wind power, tie-line power changes, inertial reductions, and time delays remains almost unchanged.

Robust Delay-Dependent Load Frequency Control of Wind Power System Based on a Novel Reconstructed Model

This paper proposes an interconnection and damping assignment passivity-based control (IDA-PBC) for multimachine power systems including hydro-turbine governing systems (HTGS) with surge tank. The main objective is to stabilize the rotor speed and regulate the terminal voltage of each synchronous machine in a power system. The proposed control is decentralized, thus avoiding challenges of communication between generators. Passivity theory is used since the open-loop of the HTGS presents a port-Hamiltonian structure. IDA-PBC allows a control law that maintains the passive structure in closed-loop, guaranteeing its asymptotic stability using Lyapunov's theory. The dynamics of each HTGS are described by an eleventh-order model, which can be reduced to a tenth-order. The proposed control is tested in a 12-bus test system and compared to a standard control, which considers a voltage regulator and exciter based on the IEEE type ST1A excitation system model and power system stabilizer IEEE-PSS1A. The governing system based on a PID control with static and transient droop is also employed. Additionally, the proposed controller is compared to a sliding mode controller. Time-domain simulations demonstrate the robustness and appropriate performance of the proposed decentralized control under different large disturbances.

Passivity-Based Control of Power Systems Considering Hydro-Turbine With Surge Tank

In this study, a fractional-order sliding mode control (FSMC) scheme using a recurrent neural network (RNN) approximator is introduced to achieve better control performance for a class of dynamic systems. The proposed recurrent neural network fractional-order sliding mode control (RNNFSMC) scheme combines a fractional-order control method and a RNN structure. The primary objective of the proposed RNNFSMC scheme is to construct a fractional-order sliding mode controller. The RNN estimator is applied to approximate the unknown nonlinear part online. In the case study, the proposed RNNFSMC scheme is used for a dynamic model of an active power filter to realize the current harmonic compensation control. Simulation experiment proves that the proposed scheme is effective and robust and has a good tracking effect for dynamic system.

Recurrent Neural Network Fractional-order Sliding Mode Control of Dynamic Systems

In this brief, a sliding mode (SM) decentralized excitation controller for multimachine power systems is designed to stabilize the speed and regulate the terminal voltage of each generator in the system. To achieve the speed stabilization, a sliding manifold is designed using the passivity technique. An integral SM controller is proposed to reject internal and external perturbations, taking advantage of the energy properties of the power systems, in the SM motion on the designed manifold. Then, an SM voltage regulator is included in the control scheme, and a logic control is formulated to manage two proposed control laws for the speed and terminal voltage. Finally, to estimate the unmeasured rotor fluxes a nonlinear observer is designed. The proposed control scheme was tested through simulation on an equivalent of the Western System Coordinating Council under small and large perturbations.

H. Huerta

Papers

Passivity Sliding Mode Control of Large-Scale Power Systems