State-of-the-Art on the Marine Current Turbine System Faults

This chapter deals with the state of the art on the marine current turbine (MCT) system faults. Indeed, the MCT structure consists of a marine turbine, a generator (permanent magnet synchronous generator (PMSG) or doubly fed induction generator (DFIG)), and a PWM power converter. Nevertheless, these systems are exposed to functional and environmental severe conditions. Firstly, the power increase leads to a higher current and/or voltage. Second, the installation of the MCT system under the sea and the existence of the swell and wave imply harmonic current speeds. In fact, several faults (related to the turbine, the generator, the blades, and the converters) can occur in the MCT system. Most of these faults generate the speed and the torque oscillations, which can lead to mechanical vibrations and the rapid destruction of the insulating material generator. Consequently, MCT system performances can be degraded

Marine Current Turbine System Post-Fault Behavior under an Open Circuit Fault

This paper describes the modeling and simulation of a Permanent Magnet Synchronous Generator (PMSG) based Marine Current Turbine (MCT) under converter faulty conditions. The modeling of the generator is represented in the d-q reference frame. The Proportional Integral (PI) controllers are used for the direct current, the quadratic current, and the speed Control. The faulty mode describes an open-circuit fault in the generator-side converter. Simulations results show that the dynamic performances and the power generation of the MCT are highly degraded due to the fault

Robust Control Based on Input-Output Feedback Linearization for Induction Motor Drive: Real Time Implementation

This chapter proposes a design of hardware architecture of an improved Direct Torque Control (DTC) for a real-time implementation on a Xilinx Field-Programmable Gate Array (FPGA). The first contribution in this chapter consists in combining the DTC with a Space Vector Modulation (SVM) technique and an Input-Output Feedback Linearization (IOFL) approach. In fact, the classical DTC has remarkable performance in terms of fast torque response and less dependence on the system parameters. Despite the cited advantages, the classical DTC is penalized by high torque ripples and inverter-switching-frequency variations. In this context, the SVM is added to the DTC structure in order to keep the switching frequency constant and to reduce ripples. Furthermore, the nonlinear IOFL is proposed to achieve a decoupled flux and torque control. The novel structure is named in this chapter as DTC-IOFL-SVM. Moreover, this chapter presents a hardware implementation of the suggested DTC-IOFL-SVM strategy utilization. The hardware implementation is chosen in order to reduce the sampling period of the system thanks to the parallel processing of the FPGA. In order to demonstrate the performance of the FPGA implementation of the proposed DTC-IOFL-SVM, numerous simulation results are presented using the Xilinx system generator under a Matlab/Simulink

Experimental validation of an advanced metaheuristic algorithm for maximum power point tracking of a shaded photovoltaic system: A comparative study between three approaches

Under partially shaded conditions, the power–voltage characteristic curve of the Photovoltaic System (PVS) presents more than one peak, so the Global Maximum Power Point (GMPP) cannot be detected using the conventional Maximum Power Point Tracking (MPPT) algorithms, such as the Perturb-and-Observe (P&O) algorithm. In order to overcome the limitations of the conventional MPPT algorithms, this paper suggests a metaheuristic MPPT called the Crow Search Algorithm (CSA) for the performance optimization of a standalone PVS. The CSA algorithm has the capability of attenuating the negative effects of the partial shading on the performance of the PVS by the accurate detection of the GMPP. The principle of the latter algorithm uses the crow skills and behaviors in the process of locating places to hide its food. Relative to other metaheuristic methods, the CSA utilizes only two tuning parameters that combine between simplicity of implementation and good efficiency. The simulation and experimental results under partial shading applications demonstrates the better performance of the suggested CSA algorithm compared to the particle swarm optimization and P&O algorithms. In fact, the comparison is carried out in terms of high efficiency, good accuracy, low convergence time and simplicity of implementation. Indeed, the proposed CSA-based MPPT approach extracts the maximum power produced by the PVS with an estimated average efficiency of 99.87%, whereas the PSO and P&O methods record average efficiencies of 99.39% and 95.23%, respectively. Furthermore, as compared to the PSO and P&O MPPT methods, the suggested CSA-based MPPT approach reduces convergence time by an average of 48.41% and 49.63%, respectively

Enhanced Intelligent Closed Loop Direct Torque and Flux Control of Induction Motor for Standalone Photovoltaic Water Pumping System

This paper aims to search for a high-performance low-cost standalone photovoltaic water pumping system (PVWPS) based on a three-phase induction motor (IM). In order to control the IM, a fuzzy direct torque control (FDTC) is proposed in this paper for overcoming the limitations of the conventional direct torque control (CDTC). In fact, the CDTC suffers from several problems such as torque ripples, current distortion, and switching frequency variations. These problems can be solved with the proposed FDTC. To ensure high performance of the PVWPS, the reference torque is generated using a fuzzy speed controller (FSC) instead of a conventional proportional integral speed controller. In order to extract the maximum amount of power, the proposed maximum power point tracking controller is based on variable step size perturb and observe to surmount the weakness of the conventional perturb and observe technique. The performance of the proposed FDTC based on the FSC under variable climatic conditions is demonstrated by digital simulation using Matlab/Simulink. The obtained results show the effectiveness of the suggested FDTC based on the FSC compared with the CDTC in terms of pumped water, reduction in flux and torque ripple, diminution of losses, and decrease in the stator current harmonic

Enhanced Intelligent Closed Loop Direct Torque and Flux Control of Induction Motor for Standalone Photovoltaic Water Pumping System

This paper aims to search for a high-performance low-cost standalone photovoltaic water pumping system (PVWPS) based on a three-phase induction motor (IM). In order to control the IM, a fuzzy direct torque control (FDTC) is proposed in this paper for overcoming the limitations of the conventional direct torque control (CDTC). In fact, the CDTC suffers from several problems such as torque ripples, current distortion, and switching frequency variations. These problems can be solved with the proposed FDTC. To ensure high performance of the PVWPS, the reference torque is generated using a fuzzy speed controller (FSC) instead of a conventional proportional integral speed controller. In order to extract the maximum amount of power, the proposed maximum power point tracking controller is based on variable step size perturb and observe to surmount the weakness of the conventional perturb and observe technique. The performance of the proposed FDTC based on the FSC under variable climatic conditions is demonstrated by digital simulation using Matlab/Simulink. The obtained results show the effectiveness of the suggested FDTC based on the FSC compared with the CDTC in terms of pumped water, reduction in flux and torque ripple, diminution of losses, and decrease in the stator current harmonic

Optimal Contribution of Energy Management of Electric Vehicles

An Electrical Vehicle (EV) has the advantage of being friendly with environment but it does not have the same performance as a current conventional vehicle. This work proposes a strategy to improve the EV autonomy. At first, an EV model that combines lead acid batteries and a DC motor is described. The individual mathematical model for each component is developed in MATLAB. Moreover, the control speed strategy using fuzzy logic is applied to the system to produce a maximum speed reference of an EV under different states of charge of the battery and acceleration. Then, a proportional integral control adjusts the speed strategy. When the vehicle is subjected to different scenarios, the simulation realized in MATLAB/Simulink will show good efficiency

New LiFePO 4 Battery Model Identification for Online SOC Estimation Application

International audienc

Impact d'un court-circuit interne au stator d'une machine asynchrone sur les phénomènes générés par la denture

D une manière générale l étude des machines électriques peut être entreprise suivant différents niveaux de complexité. L approche la plus simple considère une machine idéalisée pour laquelle on s intéresse aux phénomènes principaux, notamment ceux qui génèrent le couple électromagnétique moyen. Si on s intéresse aux phénomènes secondaires, parfois difficiles à appréhender, comme les bruits et vibrations, les pertes fer, ou le flux de dispersion des machines électriques, il est nécessaire d avoir une approche plus complexe. C est dans ce contexte que s inscrit notre travail dans lequel on s intéressera plus particulièrement à la machine asynchrone fonctionnant dans des régimes nonconventionnels. L originalité de notre étude réside dans l analyse, par une approche semi analytique, des phénomènes précités dans des cas d une machine présentant un défaut de court-circuit entre spires statoriques. Les objectifs de ce travail sont multiples, on s intéressera tout d abord à l étude de l effet du défaut sur les phénomènes générés par la denture de manière à pouvoir apprécier son importance sur les dégradations des performances de la machine. Le deuxième point consiste à étudier les moyens de minimisation des pertes fer et des vibrations par conception, en ajustant certains paramètres géométriques de la machine, évitant ainsi le recours à des actions extérieures comme l injectiond harmoniques de courant. Le dernier point consiste à corréler les pertes fer et les vibrations avec le champ magnétique de dispersion. Cette corrélation permet par exemple d estimer le niveau de dégradation des performances lors d un fonctionnement non conventionnel de la machine.In a general way the electrical machines study can be undertaken according to various levels of complexity. The simplest approach considers an idealized machine for which we are interested in the main phenomena, in particular those that generate the average electromagnetic torque. If we are interested in the secondary phenomena, sometimes difficult to analyze, as the vibrations and noise, the iron losses, or the external magnetic field of the electrical machines, it is necessary to have a more complex approach. It is in this context that joins our work in which we shall be interested more particularly in the induction machine working in unconventional conditions. The originality of our study lies in the analysis, by a semi analytical approach, of aforesaid phenomena in cases of a machine presenting an inter turn short circuit. The objectives of this work are multiple, we shall be interested first in the study of the effect of the default on the phenomena generated by the slotting effect so as to be able to appreciate its importance on the machine performances degradation. The second point is to explore the ways to minimize iron losses and vibration by conception, by adjusting some machine geometrical parameters, so avoiding the recourse to outside actions as the current harmonic injection. The last point consists in correlating the iron losses and the vibrations to the external magnetic field. This correlation allows for example to estimate the performance degradation level during a machine unconventional running.ARRAS-Bib.electronique (620419901) / SudocSudocFranceF