A coupled electromagnetic / hydrodynamic model for the design of an integrated rim - driven naval propulsion system

This paper presents an analytical multi-physic modeling tool for the design optimization of a new kind of naval propulsion system. This innovative technology consists in an electrical permanent magnet motor that is integrated into a duct and surrounds a propeller. Compared with more conventional systems such as pods, the electrical machine and the propeller have the same diameter. Thus, their geometries, in addition to speed and torque, are closely related and a multidisciplinary design approach is relevant. Two disciplines are considered in this analytical model: electromagnetism and hydrodynamics. An example of systematic design for a typical application (a rim-driven thruster for a patrol boat) is then presented for a set of different design objectives (efficiency, mass, etc). The effects of each model are commente

Marine Tidal Current Electric Power Generation Technology: State of the Art and Current Status

This work is supported by Brest Métropole Océane (BMO) and the European Social Fund (ESF). It is done within the framework of the Marine Renewable Energy Commission of the Brittany Maritime Cluster (Pôle Mer Bretagne).International audienceThe potential of electric power generation from marine tidal currents is enormous. Tidal currents are being recognized as a resource to be exploited for the sustainable generation of electrical power. The high load factors resulting from the fluid properties and the predictable resource characteristics make marine currents particularly attractive for power generation and advantageous when compared to other renewable energies. Moreover, international treaties related to climate control have triggered resurgence in development of renewable ocean energy technology. Therefore, several demonstration projects in tidal power are scheduled to capture the tidal generated coastal currents. Regarding this emerging and promising area of research, this paper reviews marine tidal power fundamental concepts and main projects around the world. It also report issues regarding electrical generator topologies associated to tidal turbines. Moreover, attempts are made to highlight future issues so as to index some emerging technologies mainly according to relevant works that have been carried out on wind turbines and on ship propellers

Generator Systems for Marine Current Turbine Applications: A Comparative Study

International audienceEmerging technologies for marine current turbines are mainly related to works that have been carried out on wind turbines and ship propellers. It is then obvious that many electric generator topologies could be used for marine current turbines. As in the wind turbine context, doubly-fed induction generators and permanent magnet generators seem to be attractive solutions for harnessing the tidal current energy. In this paper, a comparative study between these two generator types is presented and fully analyzed in terms of generated power, maintenance, and operation constraints. This comparison is done for the Raz de Sein site (Brittany, France) using a multiphysics modeling simulation tool. This tool integrates, in a modular environment, the resource model, the turbine hydrodynamic model, and generator models. Experiments have also been carried out to confirm the simulation results

Synthesis and modelling of an electrostatic induction motor

This paper deals with a new way of synthesis and modelling of electrostatic induction micromotors by means of duality rules from the magnetic induction machine. An electromechanical model based on this method is given. Then, a computational procedure based on a general lumped parameter model and an electric field calculation code, has been developed so as to simulate the dynamic working of these actuators. A comparison is made between the computation results and the model results. Satisfactory agreement between theory and simulation is obtained in most respect

A Comparative Study of Modular Axial Flux Podded Generators for Marine Current Turbines

International audienceThis research note deals with performance comparison of axial flux modular podded generators for marine current turbines (MCTs). Due to the submarine environment, maintenance operations are very hard, very costly, and strongly depending on sea conditions. In this context, the drive train reliability is a key feature for MCTs. For that purpose, a comparative study is proposed, to assess modular axial flux permanent magnet (AFPM) machines potential for reliability improvement. Thereby, designs of direct-drive modular AFPM generators for a given experimental MCT are performed. The proposed study shows that a pair number of spatially shifted AFPM machine modules, adequately associated, leads to the reduction of the electromagnetic torque ripples transmitted to the MCT shaft. Moreover, it is shown that the proposed module-based generator configuration achieves better thermal behavior. As the actives parts masses and costs are expected to be higher, compromises should be carried-out in terms of reliability and fault-tolerance

A Simulation Model for the Evaluation of the Electrical Power Potential Harnessed by a Marine Current Turbine in the Raz de Sein

This work is supported by Brest Métropole Océane (BMO) and the European Social Fund (ESF). It is done within the framework of the Marine Renewable Energy Commission of the Brittany Maritime Cluster (Pôle Mer Bretagne).International audienceThis paper deals with the development of a Matlab-Simulink model of a marine current turbine system through the modeling of the resource and the rotor. The purposes of the simulation model are two: performances and dynamic loads evaluation in different operating conditions and control system development for turbine operation based on pitch and speed control. In this case, it is necessary to find a compromise between the simulation model accuracy and the control loop computational speed. The Blade Element Momentum (BEM) approach is then used for the turbine modeling. As the developed simulation model is intended to be used as a sizing and site evaluation tool for current turbine installations, it has been applied to evaluate the extractable power from the Raz de Sein (Brittany, France). Indeed, tidal current data from the Raz de Sein are used to run the simulation model over various flow regimes and yield the power capture with time

High-Order Sliding Mode Control of a Marine Current Turbine Driven Permanent Magnet Synchronous Generator

This work is supported by Brest Métropole Océane (BMO) and the European Social Fund (ESF). It is also supported by the GDR SEEDS CNRS N°2994 under the Internal Project HYDROLE. It is done within the framework of the Marine Renewable Energy Commission of the Brittany Maritime Cluster (Pôle Mer Bretagne).International audienceThis paper deals with the speed control of a Permanent Magnet Synchronous Generator (PMSG)-based Marine Current Turbine (MCT). Indeed, to increase the generated power and therefore the efficiency of an MCT, a nonlinear controller has been proposed. PMSG has been already considered for similar applications particularly wind turbine systems using mainly PI controllers. However, such kinds of controllers do not adequately handle some of tidal resource characteristics such as turbulence and swell effects. Indeed, these may decrease the MCT performances. Moreover, PMSG parameter variations should be accounted for. Therefore, a robust nonlinear control strategy, namely high-order sliding mode control, is proposed. The proposed control strategy is inserted in a global simulation tool that accounts for the resource and the marine turbine models. Simulations using tidal current data from the Raz de Sein (Brittany, France), and experiments on a 7.5-kW real-time simulator are carried out for validation purposes

High-Order Sliding Mode Control of DFIG-Based Marine Current Turbine

This work is supported by Brest Métropole Océane (BMO) and the European Social Fund (ESF). It is also supported by the GDR SEEDS CNRS N°2994 under the Internal Project HYDROLE. It is done within the framework of the Marine Renewable Energy Commission of the Brittany Maritime Cluster (Pôle Mer Bretagne).International audienceThis paper deals with the speed control of a variable speed DFIG-based marine current turbine. Indeed, to increase the generated power and therefore the efficiency of a marine current turbine, a nonlinear controller has been proposed. DFIG has been already considered for similar applications particularly wind turbine systems using mainly PI controllers. However, such kinds of controllers do not adequately handle some of tidal resource characteristics such as turbulence and swell effects. Indeed, these may decrease marine current turbine performances. Moreover, DFIG parameter variations should be accounted for. Therefore, a robust nonlinear control strategy, namely high-order sliding mode control, is proposed. This control strategy relies on the resource and the marine turbine models that were validated by experimental data. The sensitivity of the proposed control strategy is analyzed regarding the swell effect as it is considered as the most disturbing one for the resource model. Tidal current data from the Raz de Sein (Brittany, France) are used to run simulations of a 7.5-kW prototype over various flow regimes. Simulation results are presented and fully analyzed

Une méthode générale pour modé1iser les convertisseurs statiques associés à des dispositifs magnétiques

In this paper a general method for modelling power electronics circuits associated with electromagnetic devices is presented. This model is based on the simultaneous resolution of the circuit equations and the field equations in electromagnetic devices and on a general solution for taking into account the switching of semiconductors. This method allows to consider phenomena such as eddy currents and saturation of magnetic materials in the electromagnetic devices associated with static converters. Dans cet article, nous présentons une méthode générale pour simuler les ensembles constitués de convertisseurs statiques associés à des structures magnétiques. Cette solution est basée sur la résolution simultanée des équations de type circuit du convertisseur couplées aux équations du champ dans la structure magnétique et sur une méthode générale pour gérer l'état des interrupteurs du circuit. Il est alors possible de considérer des phénomènes tels que les courants de Foucault ou la saturation des matériaux dans des structures associées à des convertisseurs

An original and natural method of coupling electromagnetic field equations with circuit equations put in a state form.

In this paper a general method of coupling static converters with electromagnetic devices is presented. This method is based on the simultaneous solution of the converter equations and the field equation in the electromagnetic devices. The equations are established in automatic way: the circuit equations are put in a state form and the field equations are discretized using FEM. An original way of linking the two systems of equations is proposed