Adel Bouallegue

Analysis of the coreless transformer in wireless battery vehicle charger

This paper mainly concentrates on development of fundamental theory associated to wireless power transfer application, specifically the wireless battery charger of electric vehicles. The primary core of the coreless transformer is integrated in the charger unit and the secondary core in the electric vehicle. In order to reach efficient power transfer through a large air gap between the windings of the wireless power transfer transformer, the principle of coupling magnetic resonance is used. Analysis of wireless charger battery coreless transformer of electric vehicle is performed through several simple and accurate expressions linked to the electric modeling. A capacitive compensation in primary and secondary winding is added to enhance the power transfer capability offering four topology cases (Parallel-Parallel, Series-Series, Series-Parallel, and Parallel-Series). Simulation results are performed for each case to compare their performances. The study shows the dominance of the Series-Parallel topology in energy efficiency point of view and thus the transmitted power yield over the same distance.

A new AMR approach for energy saving in Smart Grids using Smart Meter and partial Power Line Communication

The growing demand of energy, the capacity limitations of energy management, one-way communication, the need of an interoperability of the different standards, the security of the communication and the greenhouse gas emissions, leads to emerge a new infrastructure grid: Smart Grid. Smart Meters are one of the proposed solutions for the Smart Grid. In this paper, an AMR solution which provides enhanced end-to-end application. It is based on an energy meter with low-power microcontroller MSP430FE423A and the Power Line Communication standards. The microcontroller includes an energy metering module ESP430CEl. The aim of this work is to realize a real time pricing thanks to the proposed communication infrastructure. This solution is with great interest in economical and low carbon society point of view.

Design and implementation of constant wind speed turbine emulator using Matlab/Simulink and FPGA

In this paper we present the interests of the hardware implementation of control algorithms for constant wind speed turbine emulator based on DC-Machine. This system includes wind speed profile, mathematical model of a horizontal axis wind turbine, a separately excited DC-Machine and a fourth quadrant chopper. Modeling, simulation and implementation are realized in Matlab/Simulink environments. Unlike other works developed in this regards and through the tool XSG, algorithms will be implemented directly on FPGA. The features of this emulator are presented. Moreover, simulation results are analyzed and discussed using Simulink and XSG showing the benefits of our application.

Modeling of the coreless transformer and response to misalignment and gap variation

This paper focuses on wireless transfer power system based on Witricity technology, for resonant magnetic coupling and overviews the modeling of the coreless transformer used in the wireless system. An outline of a practical method is developed to calculate the system characteristic. An iterative process is carried out in order to find the parameter that optimizes the efficiency while minimizing the voltage across the resonant capacitors. The best modeling is the one giving the required power with the suited dimensioning and geometry. Four basic algorithms have been presented based on the impact of the issues of misalignment between the transmitter and the receiver including lateral displacement and angular tilt of the Witricity coils on the efficiency and used to detect and correct the power transfer efficiency optimization problem.

Multi-Agent modeling of a meters network used in Smart Grid

This paper presents a Multi-Agent Systems for the operation of the meters network in the Smart Grid. The Multi-Agent System is a distributed computational intelligent technique, which can be use to model autonomous decision making entities. This technology is used to provide intelligence to the meters network, facilitate the real time pricing, ensure self-healing failure, and even transforming the consumer into an active element in the control of his power consumption.

Self -correction algorithms used in performance optimization of wireless battery charger

This paper focuses on wireless power transfer based on Witricity technology, specifically wireless battery charger application for electric vehicle. In order to reach efficient power transfer, a principle of coupling magnetic resonance at high frequency is used. However, in high range frequency, several losses may offer such as peak power, switching losses as well as reducing the size of the required battery capacity. In order to avoid the batterys damage, perturb and observe maximum power point tracking algorithm connected with photovoltaic panel is performed. The main objective of this contribution based on proposing a self-correction algorithm to adjust misalignment between primary and secondary coils caused by a random parking of the electric vehicle and to produce suitable input power battery at important frequency level.

Performance evaluation of Box-Jenkins and linear-regressions methods versus the study-period's variations: Tunisian grid case

In the aim of forecasting the electricity demand in Tunisia, we have attempted in this paper to evaluate the performances of two traditional methods namely the univariate Box-Jenkins analysis (ARIMA models) and the multiple linear regressions based on economic and demographic variables (gross domestic product per capita and population). Forecasting algorithms are based on historical data period and provide results for a given future period. The evaluation of forecasting errors is calculated regarding the variation of historical data period and the future one. Forecasted results are calculated by means of the ARIMA (Autoregressive Integrated Moving Average) univariate models and their performances are compared to those of regressions models. The influence of historical data and prediction periods on forecasting performance is investigated to evaluate the minimum period that gives acceptable forecasting errors.

Misalignment controller in wireless battery charger for electric vehicle based on MPPT method and metaheuristic algorithm

This paper focuses on applying a wireless power transfer WPT technology in an electric vehicle battery charger. The wireless charger system is based on the principle of resonance inductive coupling power through a coreless transformer. The WPT system is considered as a multi parameter and multi constrained nonlinear system. The main contribution in this paper is the use of PSO and GA metaheuristic algorithms in the optimization of a transformer design regarding the impact of a lateral misalignment and the separation distance between the primary and secondary coils. To find the best global solution which is considered as the maximum efficiency in the complex system, both algorithms are compared. A perturbation-and-observation-based tracking system is developed through an efficiency sensing system to act on the misalignment issue and the car position. An additional PSO controller is performed to control the duty cycle of the boost converter in order to follows the maximum efficiency operating points of a WPT system. The discrepancy is the use of the resonant inductive coupling as a source of the MPPT so as to perturb the car position and observe the transferred. Furthermore, the modeling of a contactless transformer is optimized using metaheuristic algorithm.

A comparative performances study of different indices for optimal DG placement in distribution system

With the increase of load demand, Distributed Generation (DG) has gained a lot of interest due to its ability to reduce power losses and enhance the system voltage stability. However, a non proper DG allocation and sizing may lead to an increase in power losses and affect the distribution system stability. This paper presents a comparative study for DG placement methods based on four different indices which are voltage drop index (L-index), voltage stability margin index (VSMI), voltage performance index (VPI) and loss sensitivity factor index (LSF). The performances of these indices are evaluated regarding power losses reduction, voltage profile and voltage stability enhancement. Simulations are carried out on the 33-bus radial distribution system. The results have shown that LSF and L-index methods gives better performance compared to the others two DG placement indicators.

Frequency and misalignment P&O controller for wireless battery charger

This paper focus on the application of wireless power transfer technology in battery charger for electric vehicle. A resonant magnetic coupling is used to enhance the power transfer efficiency between a primary and secondary circuit of a coreless transformer. A sensitivity analysis for several blocks of the contactless charger including fundamental concept of coreless transformer, Class-E inverter, resonant converter, are performed and results are reported to conclude about the choice of the required design. The power transfer is approximately related to the operating frequency and the alignment between the two coils. These problems will reduce the efficiency. Two MPPT tracking algorithms based on the P & O technique are used to converge to the maximum power. The first improved algorithm controls the working frequency to operate the system at the resonance frequency and the second algorithm acts on the misalignment to align the car perfectly. Simulation result demonstrates the effectiveness of the proposed controlled method comparing to the classic system.