Author: Mohmoud Mossa
Publisher: Anchor Academic Publishing (aap_verlag)
ISBN: 3954896397
Category : Science
Languages : en
Pages : 116
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Book Description
Recently, wind electrical power systems are getting a lot of attention since they are cost competitive, environmentally clean, and safe renewable power source as compared with the fossil fuel and nuclear power generation. A special type of induction generator, called a doubly fed induction generator (DFIG), is used extensively for high-power wind applications. They are used more and more in wind turbine applications due to the ease of controllability, the high energy efficiency, and the improved power quality.This research aims to develop a method of a field orientation scheme for control both, the active and the reactive powers of a DFIG that are driven by a wind turbine. Also, the dynamic model of the DFIG, driven by a wind turbine during grid faults, is analyzed and developed, using the method of symmetrical components. Finally, this study proposes a novel fault ride-through (FRT) capability with a suitable control strategy (i.e. the ability of the power system to remain connected to the grid during faults).
Author: Muhammad H. Rashid
Publisher: Elsevier
ISBN: 0323993435
Category : Technology & Engineering
Languages : en
Pages : 1472
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Book Description
Power Electronics Handbook, Fifth Edition delivers an expert guide to power electronics and their applications. The book examines the foundations of power electronics, power semiconductor devices, and power converters, before reviewing a constellation of modern applications. Comprehensively updated throughout, this new edition features new sections addressing current practices for renewable energy storage, transmission, integration, and operation, as well as smart-grid security, intelligent energy, artificial intelligence, and machine learning applications applied to power electronics, and autonomous and electric vehicles. This handbook is aimed at practitioners and researchers undertaking projects requiring specialist design, analysis, installation, commissioning, and maintenance services. Provides a fully comprehensive work addressing each aspect of power electronics in painstaking depth Delivers a methodical technical presentation in over 1500 pages Includes 50+ contributions prepared by leading experts Offers practical support and guidance with detailed examples and applications for lab and field experimentation Includes new technical sections on smart-grid security and intelligent energy, artificial intelligence, and machine learning applications applied to power electronics and autonomous and electric vehicles Features new chapter level templates and a narrative progression to facilitate understanding
Author: Baohua Dong
Publisher:
ISBN: 9781392823828
Category : Renewable energy sources
Languages : en
Pages : 0
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Book Description
The quickly increasing, widespread use of wind generation around the world reduces carbon emissions, decreases the effects of global warming, and lowers dependence on fossil fuels. However, the growing penetration of wind power requires more effort to maintain power systems stability.This dissertation focuses on developing a novel algorithm which dynamically optimizes the proportional-integral (PI) controllers of a doubly fed induction generator (DFIG) driven by a wind turbine to increase the transient performance based on small signal stability analysis.Firstly, the impact of wind generation is introduced. The stability of power systems with wind generation is described, including the different wind generator technologies, and the challenges in high wind penetration conditions. Secondly, the small signal stability analysis model of wind turbines with DFIG is developed, including detailed rotor/grid side converter models, and the interface with the power grid. Thirdly, Particle swarm optimization (PSO) is selected to off-line calculate the optimal parameters of DFIG PI gains to maximize the damping ratios of system eigenvalues in different wind speeds. Based on the historical data, the artificial neural networks (ANNs) are designed, trained, and have the ability to quickly forecast the optimal parameters. The ANN controllers are designed to dynamically adjust PI gains online.Finally, system studies have been provided for a single machine connected to an infinite bus system (SMIB), a single machine connected to a weak grid (SMWG), and a multi machine system (MMS), respectively. A detailed analysis for MMS with different wind penetration levels has been shown according to grid code. Moreover, voltage stability improvement and grid loss reduction in IEEE 34-bus distribution system, including WT-DFIG under unbalanced heavy loading conditions, are investigated. The simulation results show the algorithm can greatly reduce low frequency oscillations and improve transient performance of DFIGs system. It realizes off-line optimization of MMS, online forecasts the optimal PI gains, and adaptively adjusts PI gains. The results also provide some useful conclusions and explorations for wind generation design, operations, and connection to the power grid.
Author: Keith Joseph Faria
Publisher:
ISBN:
Category :
Languages : en
Pages : 258
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Book Description
This thesis describes the generic modeling of a Doubly-Fed Induction Generator (DFIG) based wind turbine. The model can also represent a wind plant with a group of similar wind turbines lumped together. The model is represented as a controlled current source which injects the current needed by the grid to supply the demanded real and reactive power. The DFIG theory is explained in detail as is the rationale for representing it by a regulated current source. The complete model is then developed in the time-domain and phasor domain by the interconnection of various sub-systems, the functions of which have been described in detail. The performance of the model is then tested for steady-state and dynamic operation. The model developed can be used for bulk power system studies and transient stability analysis of the transmission system. This thesis uses as its basis a report written for NREL (1).
Author: Thomas Ackermann
Publisher: John Wiley & Sons
ISBN: 111994208X
Category : Technology & Engineering
Languages : en
Pages : 1132
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Book Description
The second edition of the highly acclaimed Wind Power in Power Systems has been thoroughly revised and expanded to reflect the latest challenges associated with increasing wind power penetration levels. Since its first release, practical experiences with high wind power penetration levels have significantly increased. This book presents an overview of the lessons learned in integrating wind power into power systems and provides an outlook of the relevant issues and solutions to allow even higher wind power penetration levels. This includes the development of standard wind turbine simulation models. This extensive update has 23 brand new chapters in cutting-edge areas including offshore wind farms and storage options, performance validation and certification for grid codes, and the provision of reactive power and voltage control from wind power plants. Key features: Offers an international perspective on integrating a high penetration of wind power into the power system, from basic network interconnection to industry deregulation; Outlines the methodology and results of European and North American large-scale grid integration studies; Extensive practical experience from wind power and power system experts and transmission systems operators in Germany, Denmark, Spain, UK, Ireland, USA, China and New Zealand; Presents various wind turbine designs from the electrical perspective and models for their simulation, and discusses industry standards and world-wide grid codes, along with power quality issues; Considers concepts to increase penetration of wind power in power systems, from wind turbine, power plant and power system redesign to smart grid and storage solutions. Carefully edited for a highly coherent structure, this work remains an essential reference for power system engineers, transmission and distribution network operator and planner, wind turbine designers, wind project developers and wind energy consultants dealing with the integration of wind power into the distribution or transmission network. Up-to-date and comprehensive, it is also useful for graduate students, researchers, regulation authorities, and policy makers who work in the area of wind power and need to understand the relevant power system integration issues.
Author: Paul C. Krause
Publisher: John Wiley & Sons
ISBN: 111802429X
Category : Technology & Engineering
Languages : en
Pages : 693
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Book Description
Introducing a new edition of the popular reference on machine analysis Now in a fully revised and expanded edition, this widely used reference on machine analysis boasts many changes designed to address the varied needs of engineers in the electric machinery, electric drives, and electric power industries. The authors draw on their own extensive research efforts, bringing all topics up to date and outlining a variety of new approaches they have developed over the past decade. Focusing on reference frame theory that has been at the core of this work since the first edition, this volume goes a step further, introducing new material relevant to machine design along with numerous techniques for making the derivation of equations more direct and easy to use. Coverage includes: Completely new chapters on winding functions and machine design that add a significant dimension not found in any other text A new formulation of machine equations for improving analysis and modeling of machines coupled to power electronic circuits Simplified techniques throughout, from the derivation of torque equations and synchronous machine analysis to the analysis of unbalanced operation A unique generalized approach to machine parameters identification A first-rate resource for engineers wishing to master cutting-edge techniques for machine analysis, Analysis of Electric Machinery and Drive Systems is also a highly useful guide for students in the field.
Author: Ifte Khairul Amin
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
Wind energy has emerged as one of the fastest growing renewable energy sources since mid-80's due to its low cost and environmentally friendly nature compared to conventional fossil fuel based power generation. Current technologies for the design and implementation of wind energy conversion systems (WECSs) include induction generator and synchronous generator based units. The doubly fed induction generator (DFIG) is chosen in this thesis because of its economic operation, ability to regulate in sub-synchronous or super-synchronous speed and decoupled control of active and reactive powers. Among the major challenges of wind energy conversion system, extraction of maximum power from intermittent generation and supervision on nonlinear system dynamics of DFIG-WECS are of critical importance. Maximization of the power produced by wind turbine is possible by optimizing tip-speed ratio (TSR), turbine rotor speed or torque and blade angle. The literature reports that a vast number of investigations have been conducted on the maximum power point tracking (MPPT) of wind turbines. Among the reported MPPT control algorithms, the hill climb search (HCS) method is typically preferred because of its simple implementation and turbine parameter-independent scheme. Since the conventional HCS algorithm has few drawbacks such as power fluctuation and speed-efficiency trade-off, a new adaptive step size based HCS controller is developed in this thesis to mitigate its deficiencies by incorporating wind speed measurement in the controller. In addition, a common practice of using linear state-feedback controllers is prevalent in speed and current control of DFIG-based WECS. Traditional feedback linearization controllers are sensitive to system parameter variations and disturbances on grid-connected WECS, which demands advanced control techniques for stable and efficient performance considering the nonlinear system dynamics. An adaptive backstepping based nonlinear control (ABNC) scheme with iron-loss minimization algorithm for RSC control of DFIG is developed in this research work to obtain improved dynamic performance and reduced power loss. The performance of the proposed controller is tested and compared with the benchmark tuned proportional-integral (PI) controller under different operating conditions including variable wind speed, grid voltage disturbance and parameter uncertainties. Test results demonstrate that the proposed method exhibits excellent performance on the rotor side and grid side converter control. In addition, the compliance with the modern grid-code requirements is achieved by featuring a novel controller with disturbance rejection mechanism. In order to reduce the dependency on system's mathematical model, a low computational adaptive network fuzzy interference system (ANFIS) based neuro-fuzzy logic controller (NFC) scheme is developed for DFIG based WECS. The performance of the proposed NFC based DFIG-WECS is tested in simulation to regulate both grid and rotor side converters under normal and voltage dip conditions. Furthermore, a new optimization technique known as grey wolf optimization (GWO) is also designed to regulate the battery power for DFIG driven wind energy system operating in standalone mode. In order to verify the effectiveness of the proposed control schemes, simulation models are designed using Matlab/Simulink. The proposed model for MPPT and nonlinear control of grid-connected mode and GWO based power control of standalone DFIG-WECS has been successfully implemented in the real-time environment using DSP controller board DS1104 for a laboratory 480 VA DFIG. The comparison among different controllers suggests that each control technique has its own specialty in wind power control application with specific merits and shortcomings. However, the PI controller provides fast convergence, the ANFIS based NFC controller has better adaptability under grid disturbances and ABNC has moderate performance. Overall, the thesis provides a detailed overview of different robust control techniques for DFIG driven WECS in grid-connected and standalone operation mode with practical implementation.
Author: Kamila Nieradzinska
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
This thesis presents a comprehensive study on the operation, principles and theory of wind farms consisting of doubly-fed induction (DFIG) and fully-rated converter (FRC) wind generators working together in a hybrid arrangement. The main objective of this study is to develop control strategies for the hybrid arrangement of wind turbines in order to improve the grid code compliance of the overall wind farm by exploiting the unique characteristics of both technologies to support each other in case of a fault happening. As a result, this thesis presents a novel control strategy for fully rated converter wind generators to improve the fault ride through capabilities of DFIG wind turbines during an AC voltage sag. The developed controller enables the creation of an environment where the FRC and DFIG technologies coexist for the purpose of compliance of grid code requirements. This type of environment can be created in both new wind farm developments and in already deployed DFIG-based wind farms where the addition of FRCs results in the overall improvement of the grid code compliance of the wind farm.The novel controller developed in this thesis uses the FRC to supply reactive power to the hybrid wind farm network during faults with the objective of reducing the magnitude of the voltage dip. This has positive effects in DFIG rotor speed and DC voltage variables during and after the fault period. These variables, as explained in the thesis, play a crucial role in stabilising the dynamic fault ride through capabilities of the turbine. Additionally, the novel controller developed in this thesis does not compromise the integrity of the FRC system.This thesis also contributes to the investigation of hybrid wind farms connected to the main grid using voltage source converter high-voltage direct current (VSC-HVDC) as a mean to increase renewable energy penetration and transmission capacity without affecting voltage stability or power quality of the specific case of the Great Britain's (GB) network. One main control approach was investigated on the sending-end converter to integrate offshore wind power from hybrid network where all generated power is injected to the point-to-point DC link with a stiff AC bus at the wind farm network. Additionally, two possible connection topologies of future VSC-HVDC were investigated for steady state and transient conditions. The operation of a multi terminal DC network (MTDC) for hybrid offshore wind farms is analysed with power flow studies of a 5-terminal MTDC model regulated by droop control.Finally, this thesis investigates three VSC-HVDC connections schemes designed to transfer 2.4GW of power from two separate Dogger Bank wind farms to the GB grid, in terms of the investment costs, controllability and reliability against expected scenarios. The benefits and drawbacks of all three scenarios are highlighted. These include the benefits of auxiliary cables on AC and DC site of the multi-terminal connections.
Author: Jiawei Dong
Publisher:
ISBN: 9781392024164
Category : Wind energy conversion systems
Languages : en
Pages : 260
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Book Description
In this thesis, a Type III (Doubly Fed Induction Generator) wind generation system is analyzed and modeled. The results of this analysis are used to design and build a testbed for protection design and testing. The specic generator modeled is the four-pole, 10HP DFIG driven by a four-pole, 10HP induction machine powered by an adjustable speed drive. The testbed is made for research and development to analyze the DFIG during fault conditions. A future goal for the overall project is to design protection equipment for wind farms. The thesis presents the steady-state modelling and dynamic modelling of the DFIG, followed by a detailed switching model of the two-level voltage source converter (VSC). Two VSCs form a back-to-back converter which connects between the rotor windings and the power system. The grid side converter (GSC) interacts with the power system and the DC bus and is designed to maintain a constant DC bus voltage. The GSC is controlled to exchange power between the DC bus and the power system while tracking the system frequency. The power circuit, sensor circuit and control circuit for GSC are first designed and validated in simulation, then implemented in hardware. The protection logic is designed to protect the power electronics from overcurrent and overvoltage. The power control of the DFIG is achieved by rotor side converter (RSC) control strategies. The functionality of the RSC control is validated with simulation and could be implemented in hardware with similar hardware setups as the GSC.
Author: Gonzalo Abad
Publisher: Wiley-IEEE Press
ISBN: 9780470768655
Category : Technology & Engineering
Languages : en
Pages : 640
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Book Description
This book will be focused on the modeling and control of the DFIM based wind turbines. In the first part of the book, the mathematical description of different basic dynamic models of the DFIM will be carried out. It will be accompanied by a detailed steady-state analysis of the machine. After that, a more sophisticated model of the machine that considers grid disturbances, such as voltage dips and unbalances will be also studied. The second part of the book surveys the most relevant control strategies used for the DFIM when it operates at the wind energy generation application. The control techniques studied, range from standard solutions used by wind turbine manufacturers, to the last developments oriented to improve the behavior of high power wind turbines, as well as control and hardware based solutions to address different faulty scenarios of the grid. In addition, the standalone DFIM generation system will be also analyzed.
