Inter-area Oscillations in Power Systems with Uncertainties
Inter-area Oscillations in Power Systems with Uncertainties

Author: Ilias Zenelis

Publisher:

Published: 2022

Total Pages:

ISBN-13:

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"The steadily increasing load demand and the liberalization of electricity supply industry have resulted in heavy power trades over the weak tie lines of modern wide-area power grids. This effect, compounded by the slow addition of new transmission facilities, introduces numerous stability challenges. Among them, poorly-damped inter-area oscillations pose a serious threat to safe power system operation and may lead to cascading outages and blackouts. Nowadays, power networks are complex and experience various types of uncertainties causing model inaccuracies. Thus, it is understood that conventional model-based inter-area mode monitoring and control philosophy requires reconsideration. These ideas determine the scope of this thesis, which mainly focuses on the design of data-driven damping control strategies for inter-area modes. Recognizing the potential of recently developed Wide-Area Measurement System (WAMS) technology to provide a coherent picture of the entire network in real time based on Phasor Measurement Unit (PMU) data, this work proposes two Wide-Area Damping Control (WADC) algorithms against inter-area oscillations. Execution of the proposed schemes involves the online identification of the dynamic system state matrix from PMU measurements. A novel centralized participation factor-based WADC that can target multiple inter-area modes without affecting the rest of the modes is firstly presented. It is completely independent of the network model knowledge, while only requiring the generator inertia and damping constants as known parameters. The advantage of such control over model-based WADC is its capability to quickly adapt to operating condition variations. Additionally, the developed WADC algorithm does not require offline training, is adaptive to the selection of the PMU dataset and can be mapped to the actual power network dynamics. In order to bypass the high communication requirements and computational burden of centralized control architectures, a novel Modal Linear Quadratic Regulator (MLQR)-based sparse optimal WADC is also proposed. This methodology is purely data-driven and can directly shape the closed-loop damping features of every weakly-damped inter-area mode. Moreover, it takes into account the communication network constraints of WAMSs and demonstrates comparable performance to model-based and centralized model-free WADC. Finally, the thesis addresses the issue of small-signal stability monitoring degradation caused by high penetration of intermittent wind generation. A new data-driven Energy Storage System (ESS)-based algorithm is introduced and contributes a wind power balancing policy to improve the inter-area mode monitoring, and thus the WADC effectiveness. Case studies on the IEEE 39-bus, 68-bus and 145-bus benchmark systems validate the performance of the proposed WADC and ESS techniques"--

Inter-area Oscillations in Time Delayed Power Systems
Inter-area Oscillations in Time Delayed Power Systems

Author: Alexander Molina Cabrera

Publisher:

Published: 2018

Total Pages:

ISBN-13:

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Due to high costs in facilities and devices, power systems usually works close to their stability limits. To address the stability problems, automatic voltage regulators (AVR) and power system stabilizers (PSS) have been employed successfully but limited to local phenomena with few contributions in global dynamics in power systems. Then, the raise of wide area monitoring systems (WAMS) emerges as the path for the improvement of global dynamics (inter-area oscillations) performance using remote feedback controller. Hence, a new challenge emerges: maintain stability in a closed loop control with time delays inherent to WAMS: time delays in communications from measurements to the control centre, and extra delays from the control centre to actuators. The research was motivated by the need for modernization of power systems capable of dealing with such control difficulties in centralised WAMS for damping inter-area oscillations in power systems. The general idea of the approach is to splitting the time-delay power system control problem in two parts: the time compensation and the control of nonlinear power system. The control problem is solved by a model predictive control (MPC) with terminal cost and constraint set to handle complexities due to: nonlinearities of the power system, the large scale nature of the problem, uncertainties and multiple dynamic feature. The compensation is made by a database based time compensation solution relying on the most updated available state of the system, and the nature of solution provided by the MPC for the forward delay. The approach works in a superior hierarchic level, hence creating a decentralised coordinated strategy that manages slow global dynamics and fast local dynamics as well avoiding bad interactions between different dynamics. The integrated proposed approach is called General Network Latencies Tolerant Model Predictive Control (GNLT-MPC). The approach has been successfully tested in nonlinear time simulations.

Inter-area Oscillations in Power Systems
Inter-area Oscillations in Power Systems

Author: Arturo Roman Messina

Publisher: Springer Science & Business Media

Published: 2009-04-21

Total Pages: 278

ISBN-13: 0387895302

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The study of complex dynamic processes governed by nonlinear and nonstationary characteristics is a problem of great importance in the analysis and control of power system oscillatory behavior. Power system dynamic processes are highly random, nonlinear to some extent, and intrinsically nonstationary even over short time intervals as in the case of severe transient oscillations in which switching events and control actions interact in a complex manner. Phenomena observed in power system oscillatory dynamics are diverse and complex. Measured ambient data are known to exhibit noisy, nonstationary fluctuations resulting primarily from small magnitude, random changes in load, driven by low-scale motions or nonlinear trends originating from slow control actions or changes in operating conditions. Forced oscillations resulting from major cascading events, on the other hand, may contain motions with a broad range of scales and can be highly nonlinear and time-varying. Prediction of temporal dynamics, with the ultimate application to real-time system monitoring, protection and control, remains a major research challenge due to the complexity of the driving dynamic and control processes operating on various temporal scales that can become dynamically involved. An understanding of system dynamics is critical for reliable inference of the underlying mechanisms in the observed oscillations and is needed for the development of effective wide-area measurement and control systems, and for improved operational reliability.

Power System Oscillations
Power System Oscillations

Author: Graham Rogers

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 333

ISBN-13: 1461545617

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Power System Oscillations deals with the analysis and control of low frequency oscillations in the 0.2-3 Hz range, which are a characteristic of interconnected power systems. Small variations in system load excite the oscillations, which must be damped effectively to maintain secure and stable system operation. No warning is given for the occurrence of growing oscillations caused by oscillatory instability, since a change in the system's operating condition may cause the transition from stable to unstable. If not limited by nonlinearities, unstable oscillations may lead to rapid system collapse. Thus, it is difficult for operators to intervene manually to restore the system's stability. It follows that it is important to analyze a system's oscillatory behavior in order to understand the system's limits. If the limits imposed by oscillatory instability are too low, they may be increased by the installation of special stabilizing controls. Since the late 60s when this phenomena was first observed in North American systems, intensive research has resulted in design and installation of stabilizing controls known as power system stabilizers (PSS). The design, location and tuning of PSS require special analytical tools. This book addresses these questions in a modal analysis framework, with transient simulation as a measure of controlled system performance. After discussing the nature of the oscillations, the design of the PSS is discussed extensively using modal analysis and frequency response. In the scenario of the restructured power system, the performance of power system damping controls must be insensitive to parameter uncertainties. Power system stabilizers, when well tuned, are shown to be robust using the techniques of modern control theory. The design of damping controls, which operate through electronic power system devices (FACTS), is also discussed. There are many worked examples throughout the text. The Power System Toolbox© for use with MATLAB® is used to perform all of the analyses used in this book. The text is based on the author's experience of over 40 years as an engineer in the power industry and as an educator.

Inter-area Oscillations in Power Systems
Inter-area Oscillations in Power Systems

Author: Arturo Roman Messina

Publisher: Springer

Published: 2009-03-19

Total Pages: 275

ISBN-13: 9780387895291

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The study of complex dynamic processes governed by nonlinear and nonstationary characteristics is a problem of great importance in the analysis and control of power system oscillatory behavior. Power system dynamic processes are highly random, nonlinear to some extent, and intrinsically nonstationary even over short time intervals as in the case of severe transient oscillations in which switching events and control actions interact in a complex manner. Phenomena observed in power system oscillatory dynamics are diverse and complex. Measured ambient data are known to exhibit noisy, nonstationary fluctuations resulting primarily from small magnitude, random changes in load, driven by low-scale motions or nonlinear trends originating from slow control actions or changes in operating conditions. Forced oscillations resulting from major cascading events, on the other hand, may contain motions with a broad range of scales and can be highly nonlinear and time-varying. Prediction of temporal dynamics, with the ultimate application to real-time system monitoring, protection and control, remains a major research challenge due to the complexity of the driving dynamic and control processes operating on various temporal scales that can become dynamically involved. An understanding of system dynamics is critical for reliable inference of the underlying mechanisms in the observed oscillations and is needed for the development of effective wide-area measurement and control systems, and for improved operational reliability.

Power System Wide-area Stability Analysis and Control
Power System Wide-area Stability Analysis and Control

Author: Jing Ma

Publisher: John Wiley & Sons

Published: 2018-05-10

Total Pages: 367

ISBN-13: 1119304873

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An essential guide to the stability and control of power systems integrating large-scale renewable energy sources The rapid development of smart grids and the integration of large scale renewable energy have added daunting new layers of complexity to the long-standing problem of power system stability control. This book offers a systematic stochastic analysis of these nonlinear problems and provides comprehensive countermeasures to improve power system performance and control with large-scale, hybrid power systems. Power system stability analysis and control is by no means a new topic. But the integration of large scale renewable energy sources has added many new challenges which must be addressed, especially in the areas of time variance, time delay, and uncertainties. Robust, adaptive control strategies and countermeasures are the key to avoiding inadequate, excessive, or lost loads within hybrid power systems. Written by an internationally recognized innovator in the field this book describes the latest theory and methods for handling power system angle stability within power networks. Dr. Jing Ma analyzes and provides control strategies for large scale power systems and outlines state-of-the-art solutions to the entire range of challenges facing today’s power systems engineers. Features nonlinear, stochastic analysis of power system stability and control Offers proven countermeasures to optimizing power system performance Focuses on nonlinear time-variance, long time-delays, high uncertainties and comprehensive countermeasures Emphasizes methods for analyzing and addressing time variance and delay when integrating large-scale renewable energy Includes rigorous algorithms and simulations for the design of analysis and control modeling Power System Wide-area Stability Analysis and Control is must-reading for researchers studying power system stability analysis and control, engineers working on power system dynamics and stability, and graduate students in electrical engineering interested in the burgeoning field of smart, wide-area power systems.

Small-Signal Stability Analysis of Power Systems Integrated with Variable Speed Wind Generators
Small-Signal Stability Analysis of Power Systems Integrated with Variable Speed Wind Generators

Author: Wenjuan Du

Publisher: Springer

Published: 2018-09-03

Total Pages: 362

ISBN-13: 3319941682

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This book reviews and examines how power system low-frequency power oscillations and sub-synchronous oscillations may be affected by grid connection of wind power generation. Grid connection of wind power generation affects the power system small-signal stability and has been one of the most actively pursued research subjects in power systems and power electronics engineering in the last ten years. This book is the first of its kind to cover the impact of wind power generation on power system low-frequency oscillations and sub-synchronous oscillations. It begins with a comprehensive overview of the subject and progresses to modeling of power systems and introduces the application of conventional methods, including damping torque analysis, modal analysis and frequency-domain analysis, presented with detailed examples, making it useful for researchers and engineers worldwide.