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).

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

Wind Energy Systems: Modeling, Analysis and Control with DFIG provides key information on machine/converter modelling strategies based on space vectors, complex vector, and further frequency-domain variables. It includes applications that focus on wind energy grid integration, with analysis and control explanations with examples. For those working in the field of wind energy integration examining the potential risk of stability is key, this edition looks at how wind energy is modelled, what kind of control systems are adopted, how it interacts with the grid, as well as suitable study approaches. Not only giving principles behind the dynamics of wind energy grid integration system, but also examining different strategies for analysis, such as frequency-domain-based and state-space-based approaches. - Focuses on real and reactive power control - Supported by PSCAD and Matlab/Simulink examples - Considers the difference in control objectives between ac drive systems and grid integration systems

Due to environmental pollution and climate change, the use of renewable energy sources as an alternative means of power generation is on the rise globally. This is because of their clean nature, which makes them ecofriendly with little or no pollution compared to the traditional fossil fuel power-generation power plants. Among the various renewable energy sources, wind energy is one of the most widely employed, due to its promising technology. Wind turbine technologies could be classified into two groups as follows: Fixed Speed Wind Turbines (FSWTs) and Variable Speed Wind Turbines (VSWTs). There have been tremendous improvements in wind turbine technology over the years, from FSWTs to VSWTs, as a result of fast innovations and advanced developments in power electronics. Thus, the VSWTs have better wind energy capture and conversion efficiencies, less acoustic noise and mechanical stress, and better power quality in power grids without support from external reactive power compensators due to the stochastic nature of wind energy. The two most widely employed VSWTs in wind farm development are the Doubly Fed Induction Generator (DFIG) and the Permanent Magnet Synchronous Generator (PMSG) wind turbines. In order to solve transient stability intricacies during power grid faults, this book proposes different control strategies for the DFIG and PMSG wind turbines.

Master's Thesis from the year 2014 in the subject Engineering - Power Engineering, grade: 7.8, Ajay Kumar Garg Engineering College, course: M.Tech, language: English, abstract: Wind generation has become the most important alternate energy source and has experienced increased progress in India during the past decade. While it has great potential as an alternative to less environmentally friendly energy sources, there are various technical challenges that cause wind to be considered negatively by many utilities. Wind energy conversion systems suffer from the fact that their real power generation is closely dependent on the local environmental conditions. The Doubly Fed Induction Generator (DFIG) based wind turbine with variable-speed variable-pitch control scheme is the most popular wind power generator in the wind power industry. This machine can be operated either in grid connected or standalone mode. In this thesis, a detailed electromechanical model of a DFIG-based wind turbine connected to power grid as well as separately operated wind turbine system with different sub-systems is developed in the MATLAB/SIMULINK environment and its equivalent generator and turbine control structure is realized. In this regard following configurations have been considered: • DFIG with Battery storage sub-system • DFIG with Buck-Boost converter • DFIG with transformer • DFIG with 3-winding transformer Addition of battery storage and buck-boost converter sub-systems into the system enables not only dispatching of generator power but also decreases the variability in their reactive power requirements. The full control over both active and reactive power is possible by the use of transformer between DFIG and rotor side converter. The steady state behavior of the overall wind turbine system is presented and the steady state reactive power ability of the DFIG is analyzed. It has been shown that major part of the reactive power should be supplied from rotor side converter to reduce the overall rating of the generator. The DFIG with above mentioned sub-systems is connected to grid. The total harmonic distortion analysis and efficiency are carried out. It is found that DFIG with transformer in between machine and rotor side converter has lowest THD (2.29%) and DFIG with 3-winding transformer has maximum efficiency (above 93%).

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.

Wind power penetration is rapidly increasing in today's energy generation industry. In particular, the doubly-fed induction generator (DFIG) has become a very popular option in wind farms, due to its cost advantage compared with fully rated converter-based systems. Wind farms are frequently located in remote areas, far from the bulk of electric power users, and require long transmission lines to connect to the grid. Series capacitive compensation of DFIG-based wind farm is an economical way to increase the power transfer capability of the transmission line connecting the wind farm to the grid. For example, a study performed by ABB reveals that increasing the power transfer capability of an existing transmission line from 1300 MW to 2000 MW using series compensation is 90% less expensive than building a new transmission line. However, a factor hindering the extensive use of series capacitive compensation is the potential risk of subsynchronous resonance (SSR). The SSR is a condition where the wind farm exchanges energy with the electric network, to which it is connected, at one or more natural frequencies of the electric or mechanical part of the combined system, comprising the wind farm and the network, and the frequency of the exchanged energy is below the fundamental frequency of the system. This oscillatory phenomenon may cause severe damage in the wind farm, if not prevented. Therefore, this book studies the SSR phenomenon in a capacitive series compensated wind farm. A DFIG-based wind farm, which is connected to a series compensated transmission line, is considered as a case study. The book consists of two main parts: Small-signal modeling of DFIG for SSR analysis: This part presents a step-by-step tutorial on modal analysis of a DFIG-based series compensated wind farm using Matlab/Simulink. The model of the system includes wind turbine aerodynamics, a 6th order induction generator, a 2nd order two-mass shaft system, a 4th order series compensated transmission line, a 4th order rotor-side converter (RSC) controller and a 4th order grid-side converter (GSC) controller, and a 1st order DC-link model. The relevant modes are identified using participation factor analysis. Definition of the SSR in DFIG-based wind farms: This part mainly focuses on the identification and definition of the main types of SSR that occur in DFIG wind farms, namely: (1) induction generator effect (SSIGE), (2) torsional interactions (SSTI), and (3) control interactions (SSCI).