Download or read book Dynamic Voltage Stability Augmentation in Interconnected Power Systems with Renewable Energy written by Md. Jahangir Hossain and published by . This book was released on 2010 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first contribution of this dissertation is the case studies for capturing the development of different types of dynamic voltage instability, in both the short- and long-term, caused by the dynamics of different power system devices, especially induction machines. In addition, it investigates how the changing nature of systems and their dynamic behaviours cause critical issues that limit the large-scale integration of wind generators and flexible AC transmission system (FACTS) devices. A second and unique contribution of this thesis is the presentation of a method to bound unmodelled nonlinear dynamics and to design excitation control for the enhancement of large-disturbance voltage stability in power systems with significant induction motor loads. A new technique is developed which captures the full nonlinearity of systems in the region of interest. The nonlinear power system model is reformulated with a linear and a nonlinear term. The nonlinear term is the Cauchy remainder in the Taylor series expansion and in this thesis its bound is used in robust control design. This dissertation also presents an algorithm for the design of a decentralised robust controller for static synchronous compensators (STATCOMs) which results in a significant increase in the available dynamic transfer capability of a power system in the presence of fixed-speed induction generators (FSIGs). Another significant contribution of this research is the design of robust controllers which augment the low-voltage ride-through capability of FSIGs during severe disturbances. Control algorithms, using both structured and unstructured uncertainty representations, are developed for the stabilisation of faulted systems under different operating conditions. The performance of the proposed control schemes fulfils the criteria for robust stability and performance, and produces adequate stability margins for a range of test cases. The effectiveness of the suggested control strategies are validated by detailed simulations with complete nonlinear model of the devices. The performances of the designed controllers are also compared with those of conventional controllers. Simulation results show that both the dynamic voltage stability and the transient stability of a power system can be improved by the use of the robust control methods presented in this thesis.

Download or read book Robust Control for Grid Voltage Stability High Penetration of Renewable Energy written by Jahangir Hossain and published by Springer. This book was released on 2014-07-07 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book makes the area of integration of renewable energy into the existing electricity grid accessible to engineers and researchers. This is a self-contained text which has models of power system devices and control theory necessary to understand and tune controllers in use currently. The new research in renewable energy integration is put into perspective by comparing the change in the system dynamics as compared to the traditional electricity grid. The emergence of the voltage stability problem is motivated by extensive examples. Various methods to mitigate this problem are discussed bringing out their merits clearly. As a solution to the voltage stability problem, the book covers the use of FACTS devices and basic control methods. An important contribution of this book is to introduce advanced control methods for voltage stability. It covers the application of output feedback methods with a special emphasis on how to bound modelling uncertainties and the use of robust control theory to design controllers for practical power systems. Special emphasis is given to designing controllers for FACTS devices to improve low-voltage ride-through capability of induction generators. As generally PV is connected in low voltage distribution area, this book also provides a systematic control design for the PV unit in distribution systems. The theory is amply illustrated with large IEEE Test systems with multiple generators and dynamic load. Controllers are designed using Matlab and tested using full system models in PSSE.

Download or read book Symmetry in Renewable Energy and Power Systems written by Raúl Baños Navarro and published by MDPI. This book was released on 2021-01-21 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes original research papers related to renewable energy and power systems in which theoretical or practical issues of symmetry are considered. The book includes contributions on voltage stability analysis in DC networks, optimal dispatch of islanded microgrid systems, reactive power compensation, direct power compensation, optimal location and sizing of photovoltaic sources in DC networks, layout of parabolic trough solar collectors, topologic analysis of high-voltage transmission grids, geometric algebra and power systems, filter design for harmonic current compensation. The contributions included in this book describe the state of the art in this field and shed light on the possibilities that the study of symmetry has in power grids and renewable energy systems.

Download or read book Power System Dynamics and Stability written by Peter W. Sauer and published by . This book was released on 1998 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: For a one-semester senior or beginning graduate level course in power system dynamics. This text begins with the fundamental laws for basic devices and systems in a mathematical modeling context. It includes systematic derivations of standard synchronous machine models with their fundamental controls. These individual models are interconnected for system analysis and simulation. Singular perturbation is used to derive and explain reduced-order models.

Download or read book Voltage Stability Analysis of Interconnected Power Systems written by Salem Abdullah Al-Fahdi and published by . This book was released on 2002 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neural Control of Renewable Electrical Power Systems written by Edgar N. Sánchez and published by Springer Nature. This book was released on 2020-05-09 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents advanced control techniques that use neural networks to deal with grid disturbances in the context renewable energy sources, and to enhance low-voltage ride-through capacity, which is a vital in terms of ensuring that the integration of distributed energy resources into the electrical power network. It presents modern control algorithms based on neural identification for different renewable energy sources, such as wind power, which uses doubly-fed induction generators, solar power, and battery banks for storage. It then discusses the use of the proposed controllers to track doubly-fed induction generator dynamics references: DC voltage, grid power factor, and stator active and reactive power, and the use of simulations to validate their performance. Further, it addresses methods of testing low-voltage ride-through capacity enhancement in the presence of grid disturbances, as well as the experimental validation of the controllers under both normal and abnormal grid conditions. The book then describes how the proposed control schemes are extended to control a grid-connected microgrid, and the use of an IEEE 9-bus system to evaluate their performance and response in the presence of grid disturbances. Lastly, it examines the real-time simulation of the entire system under normal and abnormal conditions using an Opal-RT simulator.

Download or read book Voltage Control and Protection in Electrical Power Systems written by Sandro Corsi and published by Springer. This book was released on 2015-06-19 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the author’s twenty years of experience, this book shows the practicality of modern, conceptually new, wide area voltage control in transmission and distribution smart grids, in detail. Evidence is given of the great advantages of this approach, as well as what can be gained by new control functionalities which modern technologies now available can provide. The distinction between solutions of wide area voltage regulation (V-WAR) and wide area voltage protection (V-WAP) are presented, demonstrating the proper synergy between them when they operate on the same power system as well as the simplicity and effectiveness of the protection solution in this case. The author provides an overview and detailed descriptions of voltage controls, distinguishing between generalities of underdeveloped, on-field operating applications and modern and available automatic control solutions, which are as yet not sufficiently known or perceived for what they are: practical, high-performance and reliable solutions. At the end of this thorough and complex preliminary analysis the reader sees the true benefits and limitations of more traditional voltage control solutions, and gains an understanding and appreciation of the innovative grid voltage control and protection solutions here proposed; solutions aimed at improving the security, efficiency and quality of electrical power system operation around the globe. Voltage Control and Protection in Electrical Power Systems: from System Components to Wide Area Control will help to show engineers working in electrical power companies and system operators the significant advantages of new control solutions and will also interest academic control researchers studying ways of increasing power system stability and efficiency.

Download or read book ERDA Research Abstracts written by and published by . This book was released on 1975 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Small signal Stability Transient Stability and Voltage Regulation Enhancement of Power Systems with Distributed Renewable Energy Resources written by Adirak Kanchanaharuthai and published by . This book was released on 2012 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The environmental and economic impact of fossil fuel generating plants has resulted in the need to find more efficient and clean sources of electricity power generation. As an alternative, promising power generation options such as renewable energy sources, especially wind energy, are receiving increased interest. This dissertation addresses some important problems in power system operations (stability and power quality) when renewable energy resources (generation and storage) are integrated into the conventional power system. In particular, the use of energy storage (STATCOM/Battery) to enhance the small-signal stability, transient stability, and voltage regulation of an electrical power system with renewable power generation is investigated as follows. 1) A linearized model of the nonlinear power system in the region of a steady-state operating point is used in conjunction with an LMI-based control design method, including D-stability, to achieve small-signal angle and frequency stability, voltage regulation, when the system is perturbed by changes in mechanical power inputs to the synchronous generators in the system. 2) A nonlinear model of the power systems with energy storage is used with an Interconnection and Damping Assignment-Passivity-Based Control design (IDA-PBC) framework to achieve transient power angle stability along with frequency and voltage regulation after the occurrence of a large disturbance (a symmetrical three-phase short circuit transmission line fault). 3) Using the combination of the IDA-PBC control law and a reduced-order nonlinear observer, voltage regulation and system stability enhancement are simultaneously accomplished following both temporary and permanent faults. To illustrate the effectiveness of the STATCOM/Battery to enhance small-signal and transient stability, the LMI-based controller design with D-stability and IDA-PBC controller design are validated using the following simulation studies: (1) a single machine infinite bus (SMIB) (2) a two-machine (synchronous generator and doubly-fed induction generator) connected to an infinite bus. For the small-signal case, simulation results show that the proposed controller can simultaneously achieve frequency and voltage regulation along with improved transient performance. For the large-signal case, the results show that the proposed controller provides improved critical clearing times (CCTs) and an enlarged domain of attraction (DOA) along with improved frequency and voltage regulation.

Download or read book Virtual Inertia Synthesis and Control written by Thongchart Kerdphol and published by Springer Nature. This book was released on 2020-11-28 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a thorough understanding of the basic principles, synthesis, analysis, and control of virtual inertia systems. It uses the latest technical tools to mitigate power system stability and control problems under the presence of high distributed generators (DGs) and renewable energy sources (RESs) penetration. This book uses a simple virtual inertia control structure based on the frequency response model, complemented with various control methods and algorithms to achieve an adaptive virtual inertia control respect to the frequency stability and control issues. The chapters capture the important aspects in virtual inertia synthesis and control with the objective of solving the stability and control problems regarding the changes of system inertia caused by the integration of DGs/RESs. Different topics on the synthesis and application of virtual inertia are thoroughly covered with the description and analysis of numerous conventional and modern control methods for enhancing the full spectrum of power system stability and control. Filled with illustrative examples, this book gives the necessary fundamentals and insight into practical aspects. This book stimulates further research and offers practical solutions to real-world power system stability and control problems with respect to the system inertia variation triggered by the integration of RESs/DGs. It will be of use to engineers, academic researchers, and university students interested in power systems dynamics, analysis, stability and control.

Download or read book Power System Dynamic and Stability Issues in Modern Power Systems Facing Energy Transition written by Cosimo Pisani and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic stability basically deals with the interactions between the system's components. Following a disturbance, the system's variables undergo transitions that can induce oscillations in active and reactive power generation, resulting in the occurrence of voltage oscillatory modes and frequency deviation in the system. Depending on the entity of the disturbance, the small- or large-signal stability of the system under consideration can be investigated. The introduction of RES-based generation that does not participate in the network services (i.e., frequency and voltage regulation) due to lack of special controls will undoubtedly affect both the overall frequency and voltage stability. Large-scale transient stability is also a concern not to be overlooked: inverter-based wind and solar generation have different angle/speed swing behaviors with respect to traditional generation due to reduced inertia, different voltage swing behaviors due to different voltage control systems, different power flow patterns, and different displacements of synchronous generation at key locations. Therefore, although power system stability and dynamics have played a very central role in the management and study of electrical power systems thus far, it is also true that the emerging scenario requires new methodologies, technologies, and analyses. In this light, the current Special Issue aims to collect contributions (i.e., research papers and review articles) on power system dynamics and stability from experts in academia and industry.

Download or read book Computational Approaches for Voltage Stability Monitoring and Control in Power Systems written by Kangombe Joseph Makasa and published by . This book was released on 2015 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: The electric power grid is a complex, non-linear, non-stationary system comprising of thousands of components such as generators, transformers, transmission lines and advanced power electronics based control devices, and customer loads. The complexity of the grid has been further increased by the introduction of smart grid technologies. Smart grid technology adds to the traditional power grids advanced methods of communication, computation and control as well as increased use of renewable energy sources such as wind and solar farms and a higher penetration of plug-in electric vehicles among others. The smart grid has resulted in much more distributed generation, bi-directional powerflows between customers and the grid, and the semi-autonomous control of subsystems. Due to this added complexity of the grid and the need to maintain reliable, quality, efficient, economical, and environmentally friendly power supply, advanced monitoring and control technologies are needed for real-time operation of various systems that integrate into the transmission and distribution network. In this dissertation, the development of computational intelligence methods for on-line monitoring of voltage stability in a power system is presented. In order to carry out on-line assessment of voltage stability, data from Phasor Measurement Units (PMUs) is utilized. An intelligent algorithm for optimal location of PMUs for voltage stability monitoring is developed. PMU information is used for estimation of voltage stability load index in a power system with plug-in electric vehicle and wind farm included. The estimated voltage stability index is applied in the development of an adaptive dynamic programming based optimal secondary voltage controller to coordinate the reactive power capability of two FACTS devices"--Abstract, page iii.

Download or read book Long term Voltage Stability of Power Systems Under Uncertainty written by Georgia Pierrou and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The growing load demand along with the increased penetration of intermittent renewable energy sources push power systems closer to their limits. The volatile nature of demand and generation is becoming a challenging issue for power system stability properties from different aspects. To ensure the secure power system operation and power quality, uncertainty management requires more effort. This thesis concentrates on developing an analytical framework to systematically investigate and interpret the impacts of uncertainty on voltage stability and proposes novel data-driven solutions to exploit the inherent uncertainty and enhance the long-term voltage stability of power systems.As a first step, stochastic dynamic load variations are considered to formulate a stochastic dynamic power system model and analytically investigate their impact on voltage stability properties. By leveraging on bifurcation theory for the stochastic dynamic system, it is shown that the load variation intensity and the load power variation speed determine the existence of strong and weak noise regimes in which the load uncertainty may or may not affect the voltage stability margin. Moreover, the trade-off relationship of the two parameters is uncovered, providing significant insights regarding the use of energy storage to maintain a desired voltage security level. The stochastic dynamic power system model is further extended to include the renewable generation variations, such as solar and wind. Results indicate that the volatility of renewables may play a more significant role on voltage stability when load and renewable generation uncertainty coincide. After showing the potential detrimental impacts of the uncertainty on the stability margin, novel strategies are proposed to enhance grid monitoring and better support voltage stability. By exploiting the potential of Phasor Measurement Units and the abundant amount of grid data, a novel data-driven method is designed to estimate dynamic load parameters and capture the dynamic load behavior that drives the time evolution of voltages. The proposed methodology takes advantage of the regression theorem of the Ornstein-Uhlenbeck process and the properties of recursion and provides highly accurate estimation for the parameters of the dynamic load model without requiring any information about the power system model. Simulation results demonstrate the effectiveness of the method in tracking online changes of the load parameters as well as its robustness to noisy measurements.A novel online data-driven Wide-Area Voltage Control scheme which utilizes measurement data to improve voltage stability is also proposed. The proposed data-driven approach captures the load dynamics and estimates the sensitivity matrices related to voltage control. The estimation result is exploited towards the design of the control algorithm, aiming to achieve voltage restoration by controlling the on-field reactive power resources. In this direction, an online constrained optimization problem is formulated to minimize the overall voltage deviation by adjusting the voltage reference points of the voltage-controlled buses equipped with Flexible AC Transmission Devices. Numerical studies validate the performance of the data-driven Wide-Area Voltage Controller in various network topologies and combinations of voltage-controlled and voltage-uncontrolled buses as well as its robustness against erroneous or missing data"--

Download or read book Power Systems Analysis written by P.S.R. Murty and published by Butterworth-Heinemann. This book was released on 2017-06-09 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power Systems Analysis, Second Edition, describes the operation of the interconnected power system under steady state conditions and under dynamic operating conditions during disturbances. Written at a foundational level, including numerous worked examples of concepts discussed in the text, it provides an understanding of how to keep power flowing through an interconnected grid. The second edition adds more information on power system stability, excitation system, and small disturbance analysis, as well as discussions related to grid integration of renewable power sources. The book is designed to be used as reference, review, or self-study for practitioners and consultants, or for students from related engineering disciplines that need to learn more about power systems. - Includes comprehensive coverage of the analysis of power systems, useful as a one-stop resource - Features a large number of worked examples and objective questions (with answers) to help apply the material discussed in the book - Offers foundational content that provides background and review for the understanding and analysis of more specialized areas of electric power engineering

Download or read book Dynamic Analysis of Power System Voltage Stability written by Assefa Gebreselassie and published by . This book was released on 1994 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preparation of Power Distribution System for High Penetration of Renewable Energy written by Arash Khoshkbar-Sadigh and published by . This book was released on 2014 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part I: Dynamic Voltage Restorer In the present power grids, voltage sags are recognized as a serious threat and a frequently occurring power-quality problem and have costly consequence such as sensitive loads tripping and production loss. Consequently, the demand for high power quality and voltage stability becomes a pressing issue. Dynamic voltage restorer (DVR), as a custom power device, is more effective and direct solutions for "restoring" the quality of voltage at its load-side terminals when the quality of voltage at its source-side terminals is disturbed. In the first part of this thesis, a DVR configuration with no need of bulky dc link capacitor or energy storage is proposed. This fact causes to reduce the size of the DVR and increase the reliability of the circuit. In addition, the proposed DVR topology is based on high-frequency isolation transformer resulting in the size reduction of transformer. The proposed DVR circuit, which is suitable for both low- and medium-voltage applications, is based on dc-ac converters connected in series to split the main dc link between the inputs of dc-ac converters. This feature makes it possible to use modular dc-ac converters and utilize low-voltage components in these converters whenever it is required to use DVR in medium-voltage application. The proposed configuration is tested under different conditions of load power factor and grid voltage harmonic. It has been shown that proposed DVR can compensate the voltage sag effectively and protect the sensitive loads. Following the proposition of the DVR topology, a fundamental voltage amplitude detection method which is applicable in both single/three-phase systems for DVR applications is proposed. The advantages of proposed method include application in distorted power grid with no need of any low-pass filter, precise and reliable detection, simple computation and implementation without using a phased locked loop and lookup table. The proposed method has been verified by simulation and experimental tests under various conditions considering all possible cases such as different amounts of voltage sag depth (VSD), different amounts of point-on-wave (POW) at which voltage sag occurs, harmonic distortion, line frequency variation, and phase jump (PJ). Furthermore, the ripple amount of fundamental voltage amplitude calculated by the proposed method and its error is analyzed considering the line frequency variation together with harmonic distortion. The best and worst detection time of proposed method were measured 1ms and 8.8ms, respectively. Finally, the proposed method has been compared with other voltage sag detection methods available in literature. Part 2: Power System Modeling for Renewable Energy Integration As power distribution systems are evolving into more complex networks, electrical engineers have to rely on software tools to perform circuit analysis. There are dozens of powerful software tools available in the market to perform the power system studies. Although their main functions are similar, there are differences in features and formatting structures to suit specific applications. This creates challenges for transferring power system circuit models data (PSCMD) between different software and rebuilding the same circuit in the second software environment. The objective of this part of thesis is to develop a Unified Platform (UP) to facilitate transferring PSCMD among different software packages and relieve the challenges of the circuit model conversion process. UP uses a commonly available spreadsheet file with a defined format, for any home software to write data to and for any destination software to read data from, via a script-based application called PSCMD transfer application. The main considerations in developing the UP are to minimize manual intervention and import a one-line diagram into the destination software or export it from the source software, with all details to allow load flow, short circuit and other analyses. In this study, ETAP, OpenDSS, and GridLab-D are considered, and PSCMD transfer applications written in MATLAB have been developed for each of these to read the circuit model data provided in the UP spreadsheet. In order to test the developed PSCMD transfer applications, circuit model data of a test circuit and a power distribution circuit from Southern California Edison (SCE) - a utility company - both built in CYME, were exported into the spreadsheet file according to the UP format. Thereafter, circuit model data were imported successfully from the spreadsheet files into above mentioned software using the PSCMD transfer applications developed for each software. After the SCE studied circuit is transferred into OpenDSS software using the proposed UP scheme and developed application, it has been studied to investigate the impacts of large-scale solar energy penetration. The main challenge of solar energy integration into power grid is its intermittency (i.e., discontinuity of output power) nature due to cloud shading of photovoltaic panels which depends on weather conditions. In order to conduct this study, OpenDSS time-series simulation feature, which is required due to intermittency of solar energy, is utilized. In this study, the impacts of intermittency of solar energy penetration, especially high-variability points, on voltage fluctuation and operation of capacitor bank and voltage regulator is provided. In addition, the necessity to interpolate and resample unequally spaced time-series measurement data and convert them to equally spaced time-series data as well as the effect of resampling time-interval on the amount of error is discussed. Two applications are developed in Matlab to do interpolation and resampling as well as to calculate the amount of error for different resampling time-intervals to figure out the suitable resampling time-interval. Furthermore, an approach based on cumulative distribution, regarding the length for lines/cables types and the power rating for loads, is presented to prioritize which loads, lines and cables the meters should be installed at to have the most effect on model validation.

Download or read book Power System Dynamic Voltage Stability Assessment Using Artificial Network written by Suresh Packiriswamy and published by . This book was released on 2007 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: