Control of a Wind Driven Doubly Fed Induction Generator During Grid Faults

Control of a Wind Driven Doubly Fed Induction Generator During Grid Faults PDF Author: Mahmoud Mossa
Publisher: GRIN Verlag
ISBN: 3656367760
Category : Science
Languages : en
Pages : 134

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Book Description
Master's Thesis from the year 2013 in the subject Engineering - Power Engineering, grade: none, , course: Electrical engineering (Renewable energy), language: English, abstract: Wind electrical power systems are recently getting lot of attention, because they are cost competitive, environmental clean and safe renewable power source, as compared with 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 ease controllability, high energy efficiency and improved power quality. This thesis aims to develop a method of a field orientation scheme for control both the active and reactive powers of a DFIG driven by a wind turbine.The proposed control system consists of a wind turbine that drives a DFIG connected to the utility grid through AC-DC-AC link. The main control objective is to regulate the dc link voltage for operation at maximum available wind power.This is achieved by controlling the and axes components of voltages and currents for both rotor side and line side converters using PI controllers. The complete dynamic model of the proposed system is described in detail. Computer simulations have been carried out in order to validate the effectiveness of the proposed system during the variation of wind speed. The results prove that , better overall performances are achieved, quick recover from wind speed disturbances in addition to good tracking ability. Generally, any abnormalities associated with grid asymmetrical faults are going to affect the system performance considerably. During grid faults, unbalanced currents cause negative effects like overheating problems and mechanical stress due to high torque pulsations that can damage the rotor shaft, gearbox or blade assembly. Therefore, the dynamic model of the DFIG, driven by a wind turbine during grid faults has been analyzed and developed using the method of symmetrical components. The dynamic performance of the DFIG during unbalanced grid conditions is analyzed and described in detail using digital simulations. A novel fault ride-through (FRT) capability is proposed (i.e. the ability of the power system to remain connected to the grid during faults) with suitable control strategy in this thesis. In this scheme, the input mechanical energy of the wind turbine during grid faults is stored and utilized at the moment of fault clearance, instead of being dissipated in the resistors of the crowbar circuit as in the existing FRT schemes. [...]

Control of a Wind Driven Doubly Fed Induction Generator During Grid Faults

Control of a Wind Driven Doubly Fed Induction Generator During Grid Faults PDF Author: Mahmoud Mossa
Publisher: GRIN Verlag
ISBN: 3656367760
Category : Science
Languages : en
Pages : 134

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Book Description
Master's Thesis from the year 2013 in the subject Engineering - Power Engineering, grade: none, , course: Electrical engineering (Renewable energy), language: English, abstract: Wind electrical power systems are recently getting lot of attention, because they are cost competitive, environmental clean and safe renewable power source, as compared with 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 ease controllability, high energy efficiency and improved power quality. This thesis aims to develop a method of a field orientation scheme for control both the active and reactive powers of a DFIG driven by a wind turbine.The proposed control system consists of a wind turbine that drives a DFIG connected to the utility grid through AC-DC-AC link. The main control objective is to regulate the dc link voltage for operation at maximum available wind power.This is achieved by controlling the and axes components of voltages and currents for both rotor side and line side converters using PI controllers. The complete dynamic model of the proposed system is described in detail. Computer simulations have been carried out in order to validate the effectiveness of the proposed system during the variation of wind speed. The results prove that , better overall performances are achieved, quick recover from wind speed disturbances in addition to good tracking ability. Generally, any abnormalities associated with grid asymmetrical faults are going to affect the system performance considerably. During grid faults, unbalanced currents cause negative effects like overheating problems and mechanical stress due to high torque pulsations that can damage the rotor shaft, gearbox or blade assembly. Therefore, the dynamic model of the DFIG, driven by a wind turbine during grid faults has been analyzed and developed using the method of symmetrical components. The dynamic performance of the DFIG during unbalanced grid conditions is analyzed and described in detail using digital simulations. A novel fault ride-through (FRT) capability is proposed (i.e. the ability of the power system to remain connected to the grid during faults) with suitable control strategy in this thesis. In this scheme, the input mechanical energy of the wind turbine during grid faults is stored and utilized at the moment of fault clearance, instead of being dissipated in the resistors of the crowbar circuit as in the existing FRT schemes. [...]

Advanced Controls for Wind Driven Doubly Fed Induction Generators

Advanced Controls for Wind Driven Doubly Fed Induction Generators PDF Author: Mahmoud K. Abdelhamid
Publisher: CRC Press
ISBN: 1003832156
Category : Technology & Engineering
Languages : en
Pages : 212

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Book Description
Advanced Controls for Wind Driven Doubly Fed Induction Generators discusses the most advanced control algorithms used for enhancing the dynamics of a doubly fed induction generator (DFIG) operating at fixed and variable speeds, and which are used for different utilization purposes (standalone and grid connection). Extensive generator performance analysis has been introduced using various control topologies. Features: Presents modeling of wind energy conversion systems (WECS), including a wind turbine as a prime mover, a DFIG as a generation unit for electrical energy, and a three-phase induction motor as an isolated load Explores a detailed description for the presented control algorithms in order to visualize the base principle of each method Introduces a comprehensive performance analysis for the DFIG using the formulated predictive voltage control scheme and other control techniques under different operating conditions Examines the formulation of new control approaches which overcome the shortages present in previous DFIG control schemes Presents a detailed comparison between different control topologies for the DFIG to outline the most effective procedure in terms of dynamic response, structure simplicity, ripples, total harmonic distortion, and computational burdens The book is written for researchers and academics working on advanced control systems and those interested in areas such as machine drives, renewable energy systems, 'adaptive control', modeling of WECS, and optimization theory.

Modeling, Analysis and Enhancement of the performance of a Wind Driven DFIG During steady state and transient conditions

Modeling, Analysis and Enhancement of the performance of a Wind Driven DFIG During steady state and transient conditions PDF 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).

Advanced Control of Doubly Fed Induction Generator for Wind Power Systems

Advanced Control of Doubly Fed Induction Generator for Wind Power Systems PDF Author: Dehong Xu
Publisher: John Wiley & Sons
ISBN: 1119172063
Category : Science
Languages : en
Pages : 486

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Book Description
Covers the fundamental concepts and advanced modelling techniques of Doubly Fed Induction Generators accompanied by analyses and simulation results Filled with illustrations, problems, models, analyses, case studies, selected simulation and experimental results, Advanced Control of Doubly Fed Induction Generator for Wind Power Systems provides the basic concepts for modelling and controlling of Doubly Fed Induction Generator (DFIG) wind power systems and their power converters. It explores both the challenges and concerns of DFIG under a non-ideal grid and introduces the control strategies and effective operations performance options of DFIG under a non-ideal grid. Other topics of this book include thermal analysis of DFIG wind power converters under grid faults; implications of the DFIG test bench; advanced control of DFIG under harmonic distorted grid voltage, including multiple-loop and resonant control; modeling of DFIG and GSC under unbalanced grid voltage; the LFRT of DFIG, including the recurring faults ride through of DFIG; and more. In addition, this resource: Explores the challenges and concerns of Doubly Fed Induction Generators (DFIG) under non-ideal grid Discusses basic concepts of DFIG wind power system and vector control schemes of DFIG Introduces control strategies under a non-ideal grid Includes case studies and simulation and experimental results Advanced Control of Doubly Fed Induction Generator for Wind Power Systems is an ideal book for graduate students studying renewable energy and power electronics as well as for research and development engineers working with wind power converters.

Wind Driven Doubly Fed Induction Generator

Wind Driven Doubly Fed Induction Generator PDF Author: Adel Abdelbaset
Publisher: Springer
ISBN: 3319701088
Category : Technology & Engineering
Languages : en
Pages : 96

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Book Description
This book presents a modified model reference adaptive system (MRAS) observer for sensorless vector control of a wind driven doubly fed induction generator (DFIG). A mathematical model of the DFIG as influenced by core loss and main flux saturation is developed. The authors describe and evaluate grid synchronization enhancement of a wind driven DFIG using adaptive sliding mode control (SMC). Besides, grid synchronization of a wind driven DFIG under unbalanced grid voltage is also fully covered in this book.

Stability Control and Reliable Performance of Wind Turbines

Stability Control and Reliable Performance of Wind Turbines PDF Author: Kenneth Eloghene Okedu
Publisher: BoD – Books on Demand
ISBN: 178984147X
Category : Technology & Engineering
Languages : en
Pages : 198

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Book Description
This book is intended for academics and engineers working in universities, research institutes, and industry sectors wishing to acquire new information and enhance their knowledge of the current trends in wind turbine technology. Readers will gain new ideas and special experience with in-depth information about modeling, stability control, assessment, reliability, and future prospects of wind turbines. This book contains a number of problems and solutions that can be integrated into larger research findings and projects. The book enhances studies concerning the state of the art of wind turbines, modeling and intelligent control of wind turbines, power quality of wind turbines, robust controllers for wind turbines in cold weather, etc. The book also looks at recent developments in wind turbine supporting structures, noise reduction estimation methods, reliability and prospects of wind turbines, etc. As I enjoyed preparing this book, I am sure that it will be valuable for a large sector of readers.

Control Design and Analysis of Doubly-fed Induction Generator in Wind Power Application

Control Design and Analysis of Doubly-fed Induction Generator in Wind Power Application PDF Author: Shukul Mazari
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 92

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Book Description
The work presented in this thesis includes control system design, analysis and grid synchronization of a DFIG (doubly-fed induction generator) driven by a wind turbine using stator-voltage and stator-flux oriented frames. The DFIG is a special type of induction machine which is comprised of two back-to-back converters. One converter connects the DFIG stator to the grid, and the second converter is connected to the rotor of the machine through a DC-link capacitor. In this work, DFIG steady-state and transient models have been created in the d-q reference frame. The steady-state model is used to obtain the relationship between the rotor d-q currents and stator real/reactive power references in a particular orientation frame. The transient model is used to develop the DFIG power control mechanisms. The wind turbine driving torque is modeled by considering typical wind turbine aerodynamic characteristics under variable wind and pitch angle conditions. Comparisons are made to evaluate the differences between DFIG current/power controller in stator-voltage and stator-flux oriented frames. A speed control system has been designed to analyze maximum energy extraction from a DFIG for a particular wind speed. Lastly, the grid synchronization control technique and synchronization method have been proposed as this system requires some care during the machine start-up and integration with the grid. The main aim of the synchronization control process is to avoid heavy start-up currents and mechanical stresses on the turbine shaft and other integrated components. This is achieved by properly matching the phase angle, frequency, and magnitude of the grid voltage and the stator induced voltage irrespective of whether it is a stator-voltage or stator-flux oriented frame used for modeling the generator. Instead of a traditional control scheme using a PLL (phase-locked loop), the rotor d-q reference current is generated with grid voltage as the reference so as to induce identical voltage in the stator as that of the grid. The machine is started by a driving torque and the switch between stator and the grid can be closed for synchronization. However, appropriate timing of switch closure plays a critical role in satisfying the magnitude condition of synchronization. Simulation models have been developed using Matlab®/Simulink® for a GE 1.5 MW generator.

Advanced Control of Variable Speed Wind Turbine Based on Doubly-fed Induction Generator

Advanced Control of Variable Speed Wind Turbine Based on Doubly-fed Induction Generator PDF Author: Lei Wang
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This thesis deals with the modeling, control and analysis of doubly fed induction generators (DFIG) based wind turbines (DFIG-WT). The DFIG-WT is one of the mostly employed wind power generation systems (WPGS), due to its merits including variable speed operation for achieving the maximum power conversion, smaller capacity requirement for power electronic devices, and full controllability of active and reactive powers of the DFIG. The dynamic modeling of DFIG-WT has been carried out at first in Chapter 2, with the conventional vector control (VC) strategies for both rotor-side and grid-side converters. The vector control strategy works in a synchronous reference frame, aligned with the stator-flux vector, became very popular for control of the DFIG. Although the conventional VC strategy is simple and reliable, it is not capable of providing a satisfactory transient response for DFIG-WT under grid faults. As the VC is usually designed and optimized based on one operation point, thus the overall energy conversion efficiency cannot be maintained at the optimal point when the WPGS operation point moves away from that designed point due to the time-varying wind power inputs. Compared with VC methods which are designed based on linear model obtained from one operation point, nonlinear control methods can provide consistent optimal performance across the operation envelope rather than at one operation point. To improve the asymptotical regulation provided by the VC, which can't provide satisfactory performance under voltage sags caused by grid faults or load disturbance of the grid, input-output feedback linearization control (IOFLC) has been applied to develop a fully decoupled controller of the active $\&$ reactive powers of the DFIG in Chapter 3. Furthermore, a cascade control strategy is proposed for power regulation of DFIG-WT, which can provide better performance against the varying operation points and grid disturbance. Moreover, to improve the overall energy conversion efficiency of the DFIG-WT, FLC-based maximum power point tracking (MPPT) has been investigated. The main objective of the FLC-based MPPT in Chapter 4 is to design a global optimal controller to deal with the time-varying operation points and nonlinear characteristic of the DFIG-WT. Modal analysis and simulation studies have been used to verify the effectiveness of the FLC-based MPPT, compared with the VC. The system mode trajectory, including the internal zero-dynamic of the FLC-MPPT are carefully examined in the face of varied operation ranges and parameter uncertainties. In a realistic DFIG-WT, the parameter variability, the uncertain and time-varying wind power inputs are existed. To enhance the robustness of the controller, a nonlinear adaptive controller (NAC) via state and perturbation observer for feedback linearizable nonlinear systems is applied for MPPT control of DFIG-WT in Chapter 5. In the design of the controller, a perturbation term is defined to describe the combined effect of the system nonlinearities and uncertainties, and represented by introducing a fictitious state in the state equations. As follows, a state and perturbation observer is designed to estimate the system states and perturbation, leading to an adaptive output-feedback linearizing controller which uses the estimated perturbation to cancel system perturbations and the estimated states to implement a linear output feedback control law for the equivalent linear system. Case studies including with and without wind speed measurement are carried out and proved that the proposed NAC for MPPT of DFIG-WT can provide better robustness performance against the parameter uncertainties. Simulation studies for demonstrating the performance of the proposed control methods in each chapter, are carried out based on MATLAB/SIMULINK.

Analysis of Electric Machinery and Drive Systems

Analysis of Electric Machinery and Drive Systems PDF 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.

Control Method for the Wind Turbine Driven by Doubly Fed Induction Generator Under the Unbalanced Operating Conditions

Control Method for the Wind Turbine Driven by Doubly Fed Induction Generator Under the Unbalanced Operating Conditions PDF Author: Xiangpeng Zheng
Publisher:
ISBN:
Category : Electric motors, Induction
Languages : en
Pages : 112

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Book Description
Abstract: This thesis illustrates the principle and the behavior for doubly fed electric machines used in variable speed wind power systems under the balanced and unbalanced operating conditions. A generalized control method for complete stator pulsating power elimination and harmonic elimination in grid currents with adjustable power factor of a doubly fed induction generator under the unbalanced operating conditions is proposed. The theoretical analysis of this proposed control method is presented and then demonstrated by the simulation in Powersim®. The grid ride-through-fault ability by using the proposed method is also tested.