Power System Stability and Control Techniques

Power system stability encompasses the ability of the network to maintain synchronism and acceptable voltage and frequency levels in the face of disturbances. Stability phenomena are typically classified into transient, small-signal and voltage categories, each reflecting dynamic behaviour over different time scales. Transient stability relates to the response following large disturbances, such as faults or sudden loss of generation, while small-signal stability concerns low-frequency oscillations arising from normal load changes or network interactions. Control techniques range from conventional power system stabilisers inserted in generator excitation systems to advanced devices within the family of flexible AC transmission systems, such as static synchronous series compensators or unified power flow controllers. The rapid integration of renewable energy sources and distributed generation has reduced system inertia and exacerbated damping requirements for electromechanical oscillations. In response, adaptive controllers employing fuzzy logic or fractional-order algorithms and decentralised schemes using energy-storage systems have been proposed. Metaheuristic optimisation methods have been widely adopted to tune controller parameters under varying operating conditions, achieving robust performance and rapid damping. These combined approaches support the global transition to a more resilient and low-carbon electrical grid, delivering reliable power quality and system security in diverse operating contexts.

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Research from all publishers

Recent work in adaptive fractional-order control has introduced a hybrid fuzzy logic and FOPID to enhance transient stability in multi-machine networks equipped with static synchronous series compensators. The adaptive scheme dynamically adjusts control gains in real time, demonstrating significant reductions in overshoot and settling time under severe fault scenarios without manual retuning.

A hybrid optimisation approach combining a chaotic sine–cosine algorithm with pattern search has been applied to the coordinated design of power system stabilisers and SVC-based controllers. By formulating a nonlinear time-domain objective, the method balances global and local search capabilities to yield optimally damped oscillatory modes across extreme loading conditions, outperforming traditional single-stage techniques.

Innovations in swarm-based optimisation have led to an improved particle swarm algorithm for online tuning of generator stabilisers in interconnected systems. The enhanced procedure utilises a novel fitness function that integrates angular velocity deviation and overshoot metrics, enabling faster and more reliable damping of both local and inter-area oscillations compared with earlier genetic and bacteria-foraging methods.

Power System Stability and Control Techniques publication trend

The graph below shows the total number of articles in power system stability and control techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Transient stability: The ability of the power system to maintain synchronism following large disturbances such as faults or sudden generator outages.

Small-signal stability: The capacity of the system to suppress low-frequency oscillations under normal operating conditions.

Low-frequency oscillations: Electromechanical swings typically occurring in the range of 0.1–2 Hz, which may lead to system instability if insufficiently damped.

Power system stabiliser (PSS): A supplementary controller integrated into the generator excitation system to provide damping torque and mitigate electromechanical oscillations.

Fractional-order PID controller (FOPID): An extension of the conventional PID controller employing fractional calculus to add flexibility in tuning dynamic response.

Flexible AC transmission system (FACTS): Power electronic devices, such as SSSC or SVC, used to control power flows and enhance system stability.

References

1. Enhancing the transient stability of interconnected power systems by designing an adaptive fuzzy-based fractional order PID controller. Energy Reports (2024).
2. A Novel Hybrid Sine Cosine Algorithm and Pattern Search for Optimal Coordination of Power System Damping Controllers. Sustainability (2022).
3. Intelligent Design of Multi-Machine Power System Stabilizers (PSSs) Using Improved Particle Swarm Optimization. Electronics (2022).