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Lightly damped electromechanical oscillations are major operating concerns if failed to be detected at an early stage. This paper improved the existing extended complex Kalman filter (ECKF) technique of tracking electromechanical oscillations using synchrophasor measurements. The proposed algorithm adopted a distributed architecture for estimating oscillatory parameters from local substations. The novelty lies in handling maximum likelihood (ML) to enhance the convergence property in tracking multiple modes using an expectation maximization (EM) approach. This was achieved by encapsulating the augmented Lagrangian (AL) in the maximization step of the EM algorithm, which utilized a novel ECKF-based smoother (ECKS). Performance evaluations were conducted using IEEE 68-bus system and recorded synchrophasor measurements collected from the New Zealand grid. Random noise variance test cases were generated to examine the performance of the proposed algorithm. To ensure the robustness to random noisy conditions, the algorithm was tested based on exhaustive Monte Carlo simulations. Comparisons were made with the existing Prony analysis (PA), Kalman filter (KF), and distributed EM-based FB-KLPF. [ABSTRACT FROM AUTHOR]

This paper improves the existing Kalman-based technique for detecting electromechanical oscillations using Synchrophasor measurements. The novelty is the utilization of a distributed architecture to extract maximum a-posteriori (MAP) estimations of oscillatory parameters. This was achieved by an expectation maximization (EM) algorithm. To improve initial condition estimation, initial correlation information through a forward backward (FB) Kalman-like particle filter (KLPF) was integrated into the proposed scheme. Performance evaluation was conducted using IEEE New England 39-Bus system and Synchrophasor measurements collected from New Zealand Grid. The proposed method accurately extracted oscillatory parameters when the measurements were contaminated by continuous random small load fluctuations. The method also improved the capability of detecting multiple oscillations with similar frequencies. [ABSTRACT FROM PUBLISHER]

The complexity of an interconnected power system has grown exponentially with the increased load demands. These demands and stress conditions are the potential nodes in coupled system to challenge the control and stability of a multi-operational power system. Once these potential nodes are exploited, this could lead to developing stringent conditions and generation of power system oscillations which are required by the grid codes to be damped and controlled adequately. A poorly damped set of power oscillations may lead to system-wide breakups or considerably reduce the power transfer over critical channels and corridors. In recent years, a compelling need has arisen to understand the oscillation damping in the conventional and modern power grids for better performance management, control, and stability in power transfer. In this paper, a bibliographic review on the damping of power system oscillations is provided. The study identifies various control design techniques, technologies, and characteristics used in power systems. Moreover, it discusses various devices and tools to minimize damping during the era of conventional grids and renewable energy integration. The methodology of different approaches and their likely combination are discussed for different types of control design. This study also represents useful information for readers on the complete life-cycle and development phase of technology to minimize the instability variations in generating units, transmission lines, transformers, loads, and HVDC lines. A comprehensive list of publications to date in the open literature is compiled to portray a complete visual of different developments in this area. • Unstable power oscillations result in blackouts and reduced interarea power transfers. • Compel the need to understand oscillation dynamics and damping control in renewable rich grids. • Overview of analysis and control techniques, infrastructure and systems characteristics hitherto. • Classification of past and emerging oscillation frameworks from the perspective of smart grids. • Highlighting technology life cycle and development/deployment phases to minimize instability risk. • Comprehensive list of publications for a visual scenery of hitherto developments in this field. [ABSTRACT FROM AUTHOR]