Search

This paper introduces the Adaptive Coordinated Fixed-Time Synergetic Controller (ACFSC) designed for the Thyristor Controlled Series Capacitor (TCSC) and the generator excitation system. The primary objective is to enhance power system transient stability and voltage regulation performance particularly in scenarios involving unknown generator parameters. For the controller design of both generator excitation and TCSC, a linear combination of local parameters is employed to achieve the control objectives. Control laws and update laws for unknown parameters are provided for both single-machine systems connected to the infinite bus (SMIB) and multi-machine power systems. In addition, an online parameter adaptation method is proposed to further improve transient stability and achieve satisfactory voltage regulation performance in multi-machine power systems. Ultimately, the proposed nonlinear controller’s implementation is simulated in both SMIB and WSCC-type 3 power systems. The numerical results underscore significant advancements in augmenting transient stability and voltage regulation performance especially when faced with the challenge of unknown generator parameters.

The rapid expansion of wind power needs increased efforts in establishing rules for connecting wind power plants (WPPs) through grid codes and standards. This makes grid compliance testing and model validation more complex for wind turbine generator (WTG) manufacturers and WPP developers. This paper explores various challenges and solutions within the wind industry concerning grid compliance and the integration of large-scale WPPs. Traditionally, WTG original equipment manufacturers (OEMs) conduct grid compliance tests on full-scale prototype turbines, while WPP developers predominantly engage in studies for new WPPs based on offline EMT and RMS simulations. Up to this point, these approaches have sufficed to ensure grid compliance for WTGs and WPPs. However, as the wind sector progresses, new testing methods are required to meet the growing WT capacity, WPP complexity, and deployment pace, aiming to achieve society’s sustainability targets. The industry is actively exploring methodologies that address these challenges by testing new turbine subsystems and components at the development level, employing software-/hardware-in-the-loop real-time simulation for WTG/WPP interoperability assessment, and ensuring control and protection performance verification during design and operation. Additionally, digital twin approaches are being considered, encompassing the entire development and operation chain for grid compliance and connection aspects. Ultimately, this paper presents a fresh overview of these strategies, outlining definitions and the pros/cons for the stakeholders involved in the process.

This paper focuses on the challenges posed by the time-variable and nonlinear nature of energy systems. In this systems set points fluctuate due to load variations, generator losses, and disturbances such as short circuit faults. Maintaining power system stability and effectively damping low-frequency oscillations are crucial objectives. To enhance damping and dynamic stability in modern systems power system stabilizers (PSSs) are typically employed. These facilities generate auxiliary control signals for the generator excitation system, diminishing oscillations. In this study, by involving a deep deterministic policy gradient (DDPG) based on a synergetic control approach to the excitation system of synchronous generators, a novel approach to achieving fast and adaptive stability improvement and voltage regulation is suggested. The presented technique incorporates an intelligent synergetic PSS that effectively stabilizes the voltage response of a single machine connected to an infinite bus power system. To leverage its adaptive capability in controller parameter adjustments, an auxiliary deep DDPG algorithm with an Actor-Critic architecture is designed. The suggested procedure offers a promising avenue for effectively handling electromechanical oscillations and achieving improved voltage regulation and transient stability in power systems.

The effective operation of model-based control strategies in modern energy systems, characterized by significant complexity, is contingent upon highly accurate large-scale models. However, achieving such precision becomes challenging in complex energy systems rife with uncertainties and disturbances. Controlling different parts of the energy system poses a challenge to achieving optimal power system efficiency, particularly when employing model-based control strategies, thereby adding complexity to current systems. This paper proposes a novel model-independent control approach aimed at augmenting transient stability and voltage regulation performance in multi machine energy systems. The approach involves the introduction of an optimized model-free fractional-order-based excitation system stabilizer for synchronous generators in a multi machine energy system. To overcome the limitations associated with complex system model identification, which add degrees of simplification at defined operating conditions and assume the system model remains fixed despite high uncertainty and numerous disturbances, an optimal model-independent fractional-order-based excitation control strategy is introduced. The efficacy of the proposed approach is validated through comparative numerical analyses using the MATLAB/Simulink environment. These simulations were conducted on a two-area, 12-bus multi-machine power system. Simulation results demonstrate that the presented excitation system stabilizer outperforms conventional controllers in terms of transient and small-signal stability. It also suppresses the low-frequency electromechanical oscillations within the multimachine energy system.

Given the intricate nature of contemporary energy systems, addressing the control and stability analysis of these systems necessitates the consideration of highly large-scale models. Transient stability analysis stands as a crucial challenge in enhancing energy system efficiency. Power System Stabilizers (PSSs), integrated within excitation control for synchronous generators, offer a cost-effective means to bolster power systems’ stability and reliability. In this study, we propose an enhanced nonlinear control strategy based on synergetic control theory for PSSs. This strategy aims to mitigate electromechanical oscillations and rectify the limitations associated with linear approximations within large-scale energy systems that incorporate thyristor-controlled series capacitors (TCSCs). To dynamically adjust the coefficients of the nonlinear controller, we employ the Fractional Order Fish Migration Optimization (FOFMO) algorithm, rooted in fractional calculus (FC) theory. The FOFMO algorithm adapts by updating position and velocity within fractional-order structures. To assess the effectiveness of the improved controller, comprehensive numerical simulations are conducted. Initially, we examine its performance in a single machine connected to the infinite bus (SMIB) power system under various fault conditions. Subsequently, we extend the application of the proposed nonlinear stabilizer to a two-area, four-machine power system. Our numerical results reveal highly promising advancements in both control accuracy and the dynamic characteristics of controlled power systems.