Analysis and Damping Control of Power System Low-frequency Oscillations

Analysis and Damping Control of Power System Low-frequency Oscillations

Author: Haifeng Wang

Publisher: Springer

Published: 2016-03-30

Total Pages: 403

ISBN-13: 1489976965

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This book presents the research and development results on power systems oscillations in three categories of analytical methods. First is damping torque analysis which was proposed in 1960’s, further developed between 1980-1990, and widely used in industry. Second is modal analysis which developed between the 1980’s and 1990’s as the most powerful method. Finally the linearized equal-area criterion analysis that is proposed and developed recently. The book covers three main types of controllers: Power System Stabilizer (PSS), FACTS (Flexible AC Transmission Systems) stabilizer, and ESS (Energy Storage Systems) stabilizer. The book provides a systematic and detailed introduction on the subject as the reference for industry applications and academic research.


Wide-area Oscillation Identification and Damping Control in Power Systems

Wide-area Oscillation Identification and Damping Control in Power Systems

Author: Chao Lu (Mechanical engineer)

Publisher:

Published: 2018

Total Pages: 64

ISBN-13: 9781680834796

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Low-frequency oscillation (LFO) is a phenomenon inherent to power systems and should be carefully considered and dampened to improve the dynamic stability of power systems. With the development of wide area synchronous phasor measurement technology, the measurement results of phasor measurement units (PMUs) and wide-area measurement system (WAMS) can be applied in system identification and the wide area damping controller design to suppress LFO. In this paper, the identification methods and controller design methods of wide area damping control are reviewed. The basic framework for the application of PMU/WAMS results in power system identification and control is introduced first. Both the output response identification and the input-output identification are introduced in the identification section. The offline controller design and adaptive controller design methods are introduced. Practical cases in China Southern Grid and China Central Grid are reviewed as engineering application examples.


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 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"--


Coordinated Control of Inter-Area Oscillations Using Sma and Lmi

Coordinated Control of Inter-Area Oscillations Using Sma and Lmi

Author: Anamitra Pal

Publisher: LAP Lambert Academic Publishing

Published: 2012

Total Pages: 160

ISBN-13: 9783848426812

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The traditional approach to damp inter-area oscillations is through the installation of Power System Stabilizers (PSSs) which provide damping control action through excitation control systems of the generating units. However, study of recent blackouts has shown that the control action provided by a PSS alone is not sufficient for damping oscillations in modern power systems which operate under stressed conditions. An integrated form of control using remote measurements to coordinate the different control elements present in the system is the need of the hour. One way of implementing such a coordinated control is through the development of a Linear Matrix Inequality (LMI)-based polytopic model of the system that guarantees pole placement for a variety of operating conditions. The size of the polytopic formulation is an issue for application of LMIs to large systems. The use of Selective Modal Analysis (SMA) alleviates this problem by reducing the size of the system. The previous attempts have used a model containing all the and modes, with SMA being used to eliminate all the other states. In practical applications the resulting system was still found to be too large to use in a polytopic model. This thesis presents an algorithm to reduce the size of the system to the relevant modes of oscillations. A 16 machine, 68 bus equivalent model of the New England-New York interconnected power system is used as the test case with DC lines and SVCs acting as the control. The algorithm is then applied to a 127-bus equivalent model of the WECC System. The use of ESDs as a form of control is also demonstrated. The results indicate that the proposed control successfully damps the relevant modes of oscillations without negatively damping the other modes. The control is then transferred to a more detailed 4000+ bus model of the WECC system to realize its performance on real-world systems.


Interconnected Power Systems

Interconnected Power Systems

Author: Yong Li

Publisher: Springer

Published: 2015-12-23

Total Pages: 236

ISBN-13: 366248627X

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This book reports on the latest findings in the application of the wide area measurement systems (WAMS) in the analysis and control of power systems. The book collects new research ideas and achievements including a delay-dependent robust design method, a wide area robust coordination strategy, a hybrid assessment and choice method for wide area signals, a free-weighting matrices method and its application, as well as the online identification methods for low-frequency oscillations. The main original research results of this book are a comprehensive summary of the authors’ latest six-year study. The book will be of interest to academic researchers, R&D engineers and graduate students in power systems who wish to learn the core principles, methods, algorithms, and applications of the WAMS.


A Centralized Wide Area Control of Facts for Damping Power System Inter-area Oscillations

A Centralized Wide Area Control of Facts for Damping Power System Inter-area Oscillations

Author: Hany Ahmed Abdelsalam Ahmed

Publisher:

Published: 2011

Total Pages: 200

ISBN-13:

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Flexible AC Transmission Systems (FACTS) control for damping power system inter-area oscillations is a topic of much interest. However, local decentralized FACTS controllers are either too complicated to be realizable or do not offer satisfactory performance under various system operating conditions. This research develops a procedure for designing a centralized Wide Area Controller (WAC) for FACTS based on the H [infinity] method. The H [infinity] control can guarantee robust performance by minimizing the effect of certain disturbances on the inter-area oscillations. This dissertation presents a new disturbance selection method under the H [infinity] method. A transformation of the disturbance vector is derived based on the response magnitude of the inter-area modes, which significantly reduces the number of disturbances to be rejected by the controller and decreases the computational time and memory for large power systems. The proposed method is applied to the IEEE 16-machine 5-area study system with multiple FACTS devices. The results demonstrate the effectiveness of the proposed method in design of FACTS H [infinity] - WAC for large power systems.


Robust Control in Power Systems

Robust Control in Power Systems

Author: Bikash Pal

Publisher: Springer Science & Business Media

Published: 2006-07-02

Total Pages: 207

ISBN-13: 0387259503

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Robust Control in Power Systems deals with the applications of new techniques in linear system theory to control low frequency oscillations in power systems. The book specifically focuses on the analysis and damping of inter-area oscillations in the systems which are in the range of 0.2-1 Hz. The damping control action is injected through high power electronic devices known as flexible AC transmission system (FACTS) controllers. Three commonly used FACTS controllers: controllable series capacitors (CSCs) controllable phase shifters (CPSs) and static var compensators (SVCs) have been used in this book to control the inter-area oscillations. The overview of linear system theory from the perspective of power system control is explained through examples. The damping control design is formulated as norm optimization problem. The H_infinity, H2 norm of properly defined transfer functions are minimized in linear matrix inequalities (LMI) framework to obtain desired performance and stability robustness. Both centralized and decentralized control structures are used. Usually the transmission of feedback signal from a remote location encounters delays making it difficult to control the system. Smith predictor based approach has been successfully explored in this book as a solution to such a problem. Robust Control in Power Systems will be valuable to academicians in the areas of power, control and system theory, as well as professionals in the power industry.


Small-signal stability, control and dynamic performance of power systems

Small-signal stability, control and dynamic performance of power systems

Author: M.J Gibbard

Publisher: University of Adelaide Press

Published: 2015-07-15

Total Pages: 686

ISBN-13: 1925261034

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A thorough and exhaustive presentation of theoretical analysis and practical techniques for the small-signal analysis and control of large modern electric power systems as well as an assessment of their stability and damping performance.