Graham Rogers – författare

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.

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 usewith 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.

Since the publication of the first edition of this book, wide-area measurement systems (WAMS) have transformed the way that power system oscillations are monitored and studied. These systems consist of networks of time-synchronized sensors distributed over wide geographic areas—enabling new approaches not only for situational awareness but also for power system control. This fully revised and expanded edition discusses the core ideas behind WAMS, real-time situational awareness, and wide-area control as they pertain to power system oscillations. Major technological advancements since the first edition's release are covered in five new chapters. This new material highlights a first-of-its-kind demonstration project in which a 3.1 GW high-voltage direct current transmission line was used to damp inter-area oscillations in a large interconnection. It also discusses oscillations in systems dominated by inverter-based generation, including forced oscillations, which arise not from resonances but exogenous system inputs. The book includes many worked examples throughout the text using the Power System Toolbox with MATLAB, allowing readers to analyze and/or reproduce every example independently.Power System Oscillations, Second Edition, will be a valuable reference for practicing power system engineers working in the electric utility industry. Professors, students, and research scientists studying power system dynamics will also find it to be a welcomed reference text.

Since the publication of the first edition of this book, wide-area measurement systems (WAMS) have transformed the way that power system oscillations are monitored and studied. These systems consist of networks of time-synchronized sensors distributed over wide geographic areas—enabling new approaches not only for situational awareness but also for power system control. This fully revised and expanded edition discusses the core ideas behind WAMS, real-time situational awareness, and wide-area control as they pertain to power system oscillations. Major technological advancements since the first edition's release are covered in five new chapters. This new material highlights a first-of-its-kind demonstration project in which a 3.1 GW high-voltage direct current transmission line was used to damp inter-area oscillations in a large interconnection. It also discusses oscillations in systems dominated by inverter-based generation, including forced oscillations, which arise not from resonances but exogenous system inputs. The book includes many worked examples throughout the text using the Power System Toolbox with MATLAB, allowing readers to analyze and/or reproduce every example independently.Power System Oscillations, Second Edition, will be a valuable reference for practicing power system engineers working in the electric utility industry. Professors, students, and research scientists studying power system dynamics will also find it to be a welcomed reference text.

A collection of suspense stories where mystery, danger and unexpected twists combine with elements of romance. Each story explores ordinary people caught in extraordinary situations, leading to surprising and often dramatic conclusions. If you enjoy suspense with memorable characters and emotional depth, this collection is for you.

Every story begins with an ordinary moment until everything changes.This exciting collection of suspense stories will keep you turning the pages as unexpected twists, dangerous secrets, and impossible choices unfold. Each story builds the tension with gripping action, memorable characters, and surprising endings that will keep you guessing until the very last page.If you enjoy edge of your seat excitement, suspense that never lets up, and stories with unforgettable conclusions, this collection is for you.