From Dynamic Modeling to Experimentation of Induction Motor Powered by Doubly-Fed Induction Generator by Passivity-Based Control

ISBN: 978-953-307-548-8DFIG wind turbines are nowadays more widely used especially in large wind farms. The main reason for their popularity when connected to the electrical network is their ability to supply power at constant voltage and frequency while the rotor speed varies, which makes it suitable for applications with variable speed. We consider in this paper the isolated operation of a DFIG driven by a prime mover, with its stator connected to a load--which is in this case an IM. This paper presents a dynamic model of the DFIG-IM and proves that this system is Blondel-Park transformable. It is also shown that the zero dynamics is unstable for a certain operating regime. We propose and analyse different strategies for the control of the whole system mainly based on Passivity Based Control (PBC). Several of them have been implemented on a 200W DFIG interconnected with an IM prototype available in IRII-UPC (Institute of Robotics and Industrial Informatics - UPC - Barcelona). The main disadvantage of the DFIG is the slip rings, which reduce the life time of the machine and increases the maintenance costs. To overcome this drawback an alternative machine arrangement is proposed which is the Brushless Doubly Fed twin Induction Generator (BDFTIG). The system is anticipated as an advanced solution to the conventional doubly fed induction generator (DFIG). The proposed BDFTIG employs two cascaded induction machines each consisting of two wound rotors, connected in cascade to eliminate the brushes and copper rings in the DFIG. The dynamic model of BDFTIG with two machines' rotors electromechanically coupled in the back-to-back configuration is developed and implemented using Matlab/Simulink

Hydrogen Energy Storage: New Techno-Economic Emergence Solution Analysis

International audienceThe integration of various renewable energy sources as well as the liberalization of electricity markets are established facts in modern electrical power systems. The increased share of renewable sources within power systems intensifies the supply variability and intermittency. Therefore, energy storage is deemed as one of the solutions for stabilizing the supply of electricity to maintain generation-demand balance and to guarantee uninterrupted supply of energy to users. In the context of sustainable development and energy resources depletion, the question of the growth of renewable energy electricity production is highly linked to the ability to propose new and adapted energy storage solutions. The purpose of this multidisciplinary paper is to highlight the new hydrogen production and storage technology, its efficiency and the impact of the policy context on its development. A comprehensive techno/socio/economic study of long term hydrogen based storage systems in electrical networks is addressed. The European policy concerning the different energy storage systems and hydrogen production is explicitly discussed. The state of the art of the techno-economic features of the hydrogen production and storage is introduced. Using Matlab-Simulink for a power system of rated 70 kW generator, the excess produced hydrogen during high generation periods or low demand can be sold either directly to the grid owners or as filled hydrogen bottles. The affordable use of Hydrogen-based technologies for long term electricity storage is verified

Fuzzy Logic Maximum Structure and State Feedback Control Strategies of the Electrical Car

AbstractThis paper treats the design and control of different models and control strategies for an Electric Vehicle (EV). An hybrid controller is designed using a fuzzy logic integrated in Maximum Control Structure (FL-MCS), the FL nonlinear controller involves online estimation of the total reference force which corresponds to a torque reference to be applied to MCS. The second proposed regulator is a states feedback controller using the Linear Quadratic Regulation (LQR) to optimise and to determine the feedback control parameters. The LQR allows reducing the consumption of the energy according to the desired EV's dynamic performances, these lasts can be changed depending on the choice of Q and R matrices. In this work, we apply and validate the proposed control strategies by a comparison between our simulation results and the results of the classical MCS, which has been developed by L2EP (Lille, France) to control the EV speed under Matlab/Simulink

Heat management methodology for enhanced global efficiency in hybrid electric vehicles

The transportation impact on pollution and global climate change, has forced the automotive sector to search for more ecological solutions. Owing to the different properties of Fuel Cell (FC), real potential for reducing vehicles’ emissions has been witnessed. The optimization of FC integration within Electric Vehicles (EVs) is one of the original solutions. This paper presents an innovating solution of multi-stack Fuel Cell Electrical Vehicle (FCEV) in terms of efficiency, durability and ecological impact on environment. The main objective is to illustrate the interest of using the multi-stack FC system on the global autonomy, cycling, and efficiency enhancement, besides optimizing its operation performance

Voltage Flicker Recognition due to Electric Arc Furnaces via Wavelet Transform Applications

Electric Arc Furnaces (EAFs), widely used for steel production industries, are highly nonlinear time-variant disturbing loads because of the random change of the electric arc length results in arc voltage and furnace/supply current fluctuations. Consequently, Power Quality (PQ) problems such as undesirable variations of reactive power, poor power factor, harmonics, and voltage flickers may appear. The main objective of this paper is to provide the wavelet transform method for EAF to perform particular studies for Voltage Flicker Recognition. For this purpose, the mathematical equations and the dynamic model of the EAF voltage flicker are developed. Both Discrete Wavelet Transform (DWT) and Continuous Wavelet Transform (CWT) are employed to detect flicker fluctuations, estimate its duration, magnitude to eliminate the expected fluctuations. Despite nonlinearities and harmonics often encountered in EAFs, a comprehensive comparison between DWT and CWT approaches are exhibited towards enhancing PQ problems. Simulations results, via MATLABTM/Simulink, reveal that the proposed Daubechie’s DWT can be successfully used for ensuring significant decision for flicker compared to the Daubechie’s CWT approach. It is evident to mention that, the results of this study open the way to explore a new standard based on Wavelet Transform (WT) for voltage flicker recognition