Showing papers by "Franck Scuiller published in 2013"
TL;DR: In this article, an overview and the state-of-the-art of energy storage technologies for marine current energy applications are presented, and the comparison shows that high-energy batteries like sodium-sulphur battery and flow battery are favorable for smoothing the long-period power fluctuation due to the tide phenomenon while supercapacitor and flywheel are more suitable for eliminating short-term power disturbances due to swell or turbulence phenomena.
Abstract: Increasing concerns about the depletion of fossil resources and the issue of environment lead to a global need for producing more clean energy from renewable sources. Ocean is appreciated as a vast source of renewable energies. Considering marine renewable energies, it can be noticed that significant electrical power can be extracted from marine tidal currents. However, the power harnessed from marine tidal currents is highly fluctuant due to the swell effect and the periodicity of the tidal phenomenon. To improve the power quality and make the marine generation system more reliable, energy storage systems can play a crucial role. In this paper, an overview and the state of art of energy storage technologies are presented. Characteristics of various energy storage technologies are analyzed and compared for this particular application. The comparison shows that high-energy batteries like sodium-sulphur battery and flow battery are favorable for smoothing the long-period power fluctuation due to the tide phenomenon while supercapacitor and flywheel are more suitable for eliminating short-period power disturbances due to swell or turbulence phenomena. This means that hybrid storage technologies are needed for achieving optimal results in tidal marine current energy applications.
216 citations
TL;DR: In this article, a modified tip speed ratio maximum power point tracking (MPPT) algorithm with filter strategy is proposed in generator-side control to mitigate the fluctuation of generator power.
Abstract: Variations of marine current speed may lead to strong fluctuations in the power extracted by a marine current turbine (MCT). During a short-time period, swell effect is the main cause for the current speed variations. The conventional tip speed ratio maximum power point tracking (MPPT) algorithm will require the MCT to accelerate or to decelerate frequently under swell effect, which can cause severe fluctuations in the generator power. This paper focuses on power smoothing control of the grid-connected MCT system. In the first step, a modified MPPT algorithm with filter strategy is proposed in generator-side control to mitigate the fluctuation of generator power. In the second step, a supercapacitor (SC) energy storage system (ESS) is added to compensate the residual power fluctuations. Simulations of a 1.5-MW direct-driven grid-connected MCT system are carried out. The swell effect is calculated based on typical system location and sea state. Detailed control strategies and SC sizing are described. The results demonstrate that the association of the generator-side filter strategy with the SC ESS system achieves a smoothed power injected to the grid in case of swell disturbances.
107 citations
12 May 2013
TL;DR: In this paper, two power limitation strategies with flux-weakening control are investigated for a fixed-pitch marine current turbine (MCT) when the marine current speed exceeds the rated value corresponding to the rated power of generator and converter.
Abstract: This paper deals with the control strategies for a fixed-pitch marine current turbine (MCT) when the marine current speed exceeds the rated value corresponding to the rated power of generator and converter. Over-rated marine currents occur at large spring tides or under strong sea states; in these cases maximum power point tracking (MPPT) strategies must be changed to power limitation strategies for limiting the generator power at rated value. In this paper, two power limitation strategies with flux-weakening control are investigated. A feedback flux-weakening control is applied to extend the rotor speed operating range over the nominal MPPT tracking speed during high speed marine currents. In the speed control strategy, the turbine power characteristics are used to generate the rotor speed reference and the power limitation can be obtained at steady-state. In the torque control strategy, the generator torque is directly calculated by the power limitation and the rotor speed; this method enables to control the generator power at the limited value at dynamic process. Both strategies are investigated and compared at high tidal speeds without and with swell effect.
36 citations
12 May 2013
TL;DR: In this paper, the authors investigated the adaptation of the magnet shape for a low speed surface-mounted PM synchronous machine, and determined a particular trapezoid magnet shape, which almost eliminates the pulsating torque.
Abstract: This paper investigates the adaptation of the magnet shape for a low speed surface-mounted PM synchronous machine. For the considered marine propulsion application, the reduction of the ripple torques is of critical importance which explains the choice of a five-phase winding. From a multi-machine modelling of the five-phase machine, a reference back-emf spectrum is determined as design objective. To fulfill this requirement, it is decided to adapt the magnet shape. To perform this task, an analytical air gap field computation is developed and validated by using a finite element analysis software (FEMM). A particular trapezoid magnet shape is then determined for the case study. In comparison with the initial rotor made with fully pole-pitch magnets, the new magnet shape almost eliminates the pulsating torque. Furthermore, the average torque to magnet volume is improved which can be considered as a better use of the magnet material.
10 citations
TL;DR: In this paper, the authors propose a methode de modelisation and de conception adaptee aux machines a flux axial and a double Stator (poly-entrefer) destinee a etre integree comme generatrice for une hydrolienne RIM-DRIVEN de great puissance.
Abstract: Cette etude propose une methode de modelisation et de conception adaptee aux machines a flux axial et a Double Stator (poly-entrefer) destinee a etre integree comme generatrice pour une hydrolienne RIM-DRIVEN de grande puissance. La particularite du concept RIM-DRIVEN ou a entrainement circonferentiel reside dans le fait que la machine electrique se situe sur la peripherie de l'helice. De plus, dans cette etude, l'entrefer de la machine est considere immerge dans l'eau de mer. Les particularites du systeme imposent de mettre au point des modeles de dimensionnement adaptes. Ainsi, un modele electromagnetique analytique 2D inverse permettant le calcul des dimensions geometriques principales est presente. De meme, un modele thermique specifique aux machines a entrefer immerge est decrit. Ces modeles permettent d'estimer la masse et le cout des parties actives. Cette machine a flux axial est comparee en termes de couts matieres, masses et comportement thermique avec une machine a flux radial a aimants permanents dimensionnee pour un meme cahier des charges. Il en ressort clairement que la machine a flux axial double stator est thermiquement moins contrainte que les machines a simple stator.
7 citations
09 Oct 2013
TL;DR: In this paper, the authors compare the dimensionnements of generatrices of two types of structures magnetiques (a flux radial and a flux axial) for a pre-industrial pre-industrielle.
Abstract: L’article presente la comparaison des dimensionnements de generatrices a entrainement direct pour des cahiers des charges d’hydroliennes. Deux types de structures magnetiques (a flux radial et a flux axial) sont etudies.
Nous considerons que ces deux structures peuvent etre associees a une turbine a axe horizontal selon deux types de technologies d’integration : POD et Rim-Driven. Dans un concept dit « Rim-Driven » la generatrice est disposee sur la peripherie des pales. Pour les technologies POD, la generatrice est logee dans une nacelle etanche placee au niveau de
l’axe de l’helice. Un point de dimensionnement nominal inspire d’un projet d’hydrolienne preindustrielle est defini pour etre utilise, dans cette etude, pour le dimensionnement de ces generatrices. Les outils utilises comprennent un modele electromagnetique et un modele thermique integres dans une procedure d’optimisation visant a minimiser le cout total des parties actives sous contraintes thermique et de rendement. Ces dimensionnements electromagnetiques des generatrices pour des configurations Rim-Driven et POD permettent de degager des conclusions qualitatives sur le choix du type de generatrices et son mode d’accouplement avec l’helice.
01 Jan 2013
TL;DR: In this article, a modified MPPT algorithm with filter strategy is proposed in generator-side control to use the system inertia for smoothing the fluctuation of generator power when the current speed is over rated value, the power limitation control will be applied.
Abstract: Variations of marine current speed can lead to strong fluctuations in the power extracted by a marine current turbine (MCT). During short-time period, swell effect is the main cause for the current speed variations. Conventional tip speed ratio Maximum Power Point Tracking (MPPT) algorithm will require the MCT to accelerate or to decelerate frequently under swell effect, which can cause severe fluctuations in the generator power. This paper focuses on power smoothing control of a PMSG-Based MCT system. A modified MPPT algorithm with filter strategy is proposed in generator-side control to use the system inertia for smoothing the fluctuation of generator power. When the current speed is over rated value, the power limitation control will be applied. In the second step, Supercapacitor (SC) Energy Storage System (ESS) is added to compensate the residual power fluctuations. Simulations of a 1.5 MW direct- driven grid-connected MCT system are carried out. The results demonstrate that the association of the generator-side filter strategy with the SC ESS system achieves a smoothed power injected to the grid in case of swell disturbances.
09 Oct 2013
TL;DR: In this article, a modified MPPT algorithm with filter strategy is proposed in generator-side control to use the system inertia for smoothing the fluctuation of generator power when the current speed is over rated value, the power limitation control will be applied.
Abstract: Variations of marine current speed can lead to strong fluctuations in the power extracted by a marine current turbine (MCT). During short-time period, swell effect is the main cause for the current speed variations. Conventional tip speed ratio Maximum Power Point Tracking (MPPT) algorithm will require the MCT to accelerate or to decelerate frequently under swell effect, which can cause severe fluctuations in the generator power. This paper focuses on power smoothing control of a PMSG-Based MCT system. A modified MPPT algorithm with filter strategy is proposed in generator-side control to use the system inertia for smoothing the fluctuation of generator power. When the current speed is over rated value, the power limitation control will be applied. In the second step, Supercapacitor (SC) Energy Storage System (ESS) is added to compensate the residual power fluctuations. Simulations of a 1.5 MW direct-driven grid-connected MCT system are carried out. The results demonstrate that the association of the generator-side filter strategy with the SC ESS system achieves a smoothed power injected to the grid in case of swell disturbances.
01 Jan 2013
TL;DR: In this paper, a modified MPPT algorithm with filter strategy is proposed in generator-side control to use the system inertia for smoothing the fluctuation of generator power when the current speed is over rated value, the power limitation control will be applied.
Abstract: Variations of marine current speed can lead to strong fluctuations in the power extracted by a marine current turbine (MCT). During short-time period, swell effect is the main cause for the current speed variations. Conventional tip speed ratio Maximum Power Point Tracking (MPPT) algorithm will require the MCT to accelerate or to decelerate frequently under swell effect, which can cause severe fluctuations in the generator power. This paper focuses on power smoothing control of a PMSG-Based MCT system. A modified MPPT algorithm with filter strategy is proposed in generator-side control to use the system inertia for smoothing the fluctuation of generator power. When the current speed is over rated value, the power limitation control will be applied. In the second step, Supercapacitor (SC) Energy Storage System (ESS) is added to compensate the residual power fluctuations. Simulations of a 1.5 MW direct- driven grid-connected MCT system are carried out. The results demonstrate that the association of the generator-side filter strategy with the SC ESS system achieves a smoothed power injected to the grid in case of swell disturbances.