Méthodologie de choix et d'optimisation de convertisseurs d'énergie pour les applications chaînes de traction automobile

Significant research efforts have been invested in the automotive industry on alternative fuels and new hybrid electric powertrain in attempt to reduce carbon emissions from passenger cars. Fuel consumption of these hybrid powertrains strongly relies on the energy converter performance, the vehicle energetic needs, as well as on the energy management strategy deployed on-board. This thesis investigates the potential of new energy converters as substitute of actual internal combustion engine in automotive powertrain applications. Gas turbine systems is identified as potential energy converter for series hybrid electric vehicle (SHEV), as it offers many automotive intrinsic benefits such as multi-fuel capability, compactness, reduced number of moving parts, reduced noise and vibrations among others. An exergo-technological explicit analysis is conducted to identify the realistic GT-system thermodynamic configurations. A pre-design study have been carried out to identify the power to weight ratios of those systems. A SHEV model is developed and powertrain components are sized considering vehicle performance criteria. Energy consumption simulations are performed on the worldwide-harmonized light vehicles test cycle (WLTC), which account for the vehicle electric and thermal energy needs in addition to mechanical energy needs, using an innovative bi-level optimization method as energy management strategy. The intercooled regenerative reheat gas turbine (IRReGT) cycle is prioritized, offering higher efficiency and power density as well as reduced fuel consumption compared to the other investigated GT-systems. Also a dynamic model was developed and simulations were performed to account for the over fuel consumption during start-up transitory phases. Tests were also performed on some subsystems of the identified IRReGT-system. Results show improved fuel consumption with the IRReGT as auxiliary power unit (APU) compared to ICE. Consequently, the selected IRReGT-system presents a potential for implementation on futur SHEVs.D'importants efforts de recherche ont été investis dans l'industrie automobile sur les nouveaux carburants et les nouvelles chaînes de traction hybride électrique afin de réduire les émissions de carbone des véhicules. La consommation de carburant de ces groupes motopropulseurs hybrides dépend des performances du convertisseur d'énergie utilisé, des besoins énergétiques du véhicule, ainsi que de la stratégie de gestion énergétique déployée à bord. Cette thèse examine le potentiel de nouveaux convertisseurs d'énergie comme substitut du moteur thermique à combustion interne (ICE). Les systèmes de turbines à gaz sont considérés comme des convertisseurs d'énergie potentiel pour les chaînes de traction hybride série (SHEV), car ils offrent de nombreux avantages intrinsèques à l'automobile, tels que la capacité de fonctionner avec plusieurs carburants, la compacité, la réduction du nombre de pièces mobiles, la réduction du bruit et des vibrations. Une analyse exergo-technologique explicite est proposée pour identifier les configurations thermodynamiques réalistes. Une étude préconceptionnelle a été réalisée pour déterminer les rapports puissance/poids de ces systèmes. Un modèle SHEV est développé et les composants du groupe motopropulseur sont dimensionnés en fonction des critères de performance du véhicule. Des simulations de consommation sont effectuées sur le cycle d’homologation WLTC, en prenant en compte les besoins en énergie électrique et thermique du véhicule en plus des besoins en énergie mécanique, et en utilisant une méthode innovante d'optimisation comme stratégie de gestion de l'énergie. Le cycle turbine à gaz (avec compression refroidie, régénérateur et réchauffe durant la détente (IRReGT)) est priorisé car il offre un rendement et une densité de puissance plus élevés ainsi qu'une consommation de carburant réduite par rapport aux autres systèmes investigués. De plus, un modèle dynamique a été développé et des simulations ont été effectuées pour tenir compte de la surconsommation de carburant pendant les phases transitoires du démarrage. Des essais ont également été mis en œuvre sur certains sous-systèmes du cycle IRReGT identifié. Les résultats montrent une amélioration de la consommation de carburant avec l'IRReGT comme groupe auxiliaire de puissance par rapport à l'ICE. Par conséquent, le système IRReGT sélectionné présente un potentiel, non négligeable, qui remplacerait le moteur thermique à combustion interne dans les futures chaînes de traction hybride électriques

Methodology for the selection and optimization of energy converters for automotive powertrain applications

D'importants efforts de recherche ont été investis dans l'industrie automobile sur les nouveaux carburants et les nouvelles chaînes de traction hybride électrique afin de réduire les émissions de carbone des véhicules. La consommation de carburant de ces groupes motopropulseurs hybrides dépend des performances du convertisseur d'énergie utilisé, des besoins énergétiques du véhicule, ainsi que de la stratégie de gestion énergétique déployée à bord. Cette thèse examine le potentiel de nouveaux convertisseurs d'énergie comme substitut du moteur thermique à combustion interne (ICE). Les systèmes de turbines à gaz sont considérés comme des convertisseurs d'énergie potentiel pour les chaînes de traction hybride série (SHEV), car ils offrent de nombreux avantages intrinsèques à l'automobile, tels que la capacité de fonctionner avec plusieurs carburants, la compacité, la réduction du nombre de pièces mobiles, la réduction du bruit et des vibrations. Une analyse exergo-technologique explicite est proposée pour identifier les configurations thermodynamiques réalistes. Une étude préconceptionnelle a été réalisée pour déterminer les rapports puissance/poids de ces systèmes. Un modèle SHEV est développé et les composants du groupe motopropulseur sont dimensionnés en fonction des critères de performance du véhicule. Des simulations de consommation sont effectuées sur le cycle d’homologation WLTC, en prenant en compte les besoins en énergie électrique et thermique du véhicule en plus des besoins en énergie mécanique, et en utilisant une méthode innovante d'optimisation comme stratégie de gestion de l'énergie. Le cycle turbine à gaz (avec compression refroidie, régénérateur et réchauffe durant la détente (IRReGT)) est priorisé car il offre un rendement et une densité de puissance plus élevés ainsi qu'une consommation de carburant réduite par rapport aux autres systèmes investigués. De plus, un modèle dynamique a été développé et des simulations ont été effectuées pour tenir compte de la surconsommation de carburant pendant les phases transitoires du démarrage. Des essais ont également été mis en œuvre sur certains sous-systèmes du cycle IRReGT identifié. Les résultats montrent une amélioration de la consommation de carburant avec l'IRReGT comme groupe auxiliaire de puissance par rapport à l'ICE. Par conséquent, le système IRReGT sélectionné présente un potentiel, non négligeable, qui remplacerait le moteur thermique à combustion interne dans les futures chaînes de traction hybride électriques.Significant research efforts have been invested in the automotive industry on alternative fuels and new hybrid electric powertrain in attempt to reduce carbon emissions from passenger cars. Fuel consumption of these hybrid powertrains strongly relies on the energy converter performance, the vehicle energetic needs, as well as on the energy management strategy deployed on-board. This thesis investigates the potential of new energy converters as substitute of actual internal combustion engine in automotive powertrain applications. Gas turbine systems is identified as potential energy converter for series hybrid electric vehicle (SHEV), as it offers many automotive intrinsic benefits such as multi-fuel capability, compactness, reduced number of moving parts, reduced noise and vibrations among others. An exergo-technological explicit analysis is conducted to identify the realistic GT-system thermodynamic configurations. A pre-design study have been carried out to identify the power to weight ratios of those systems. A SHEV model is developed and powertrain components are sized considering vehicle performance criteria. Energy consumption simulations are performed on the worldwide-harmonized light vehicles test cycle (WLTC), which account for the vehicle electric and thermal energy needs in addition to mechanical energy needs, using an innovative bi-level optimization method as energy management strategy. The intercooled regenerative reheat gas turbine (IRReGT) cycle is prioritized, offering higher efficiency and power density as well as reduced fuel consumption compared to the other investigated GT-systems. Also a dynamic model was developed and simulations were performed to account for the over fuel consumption during start-up transitory phases. Tests were also performed on some subsystems of the identified IRReGT-system. Results show improved fuel consumption with the IRReGT as auxiliary power unit (APU) compared to ICE. Consequently, the selected IRReGT-system presents a potential for implementation on futur SHEVs

Design and simulation of turbogenerators for series hybrid electric vehicles

International audienceTo reduce emissions and fuel consumption in the automotive world, researchers are looking for alternative energy converters in the series hybrid electric vehicle and previous studies demonstrate that turbogenerator technologies are promising candidates. This study presents a methodology for the design, modelization, and dynamic simulation of different turbogenerator thermodynamic architectures to compare their performances, compute their efficiencies and select the best candidate to replace the internal combustion engine in the series hybrid electric vehicle taking into account the startup phase, where the inertia of the components affect the performance of the machine. Therefore, four types of turbogenerator configurations were thermodynamically investigated. Then an extensive work was conducted to design the turbomachines components with high efficiencies, followed by a design procedure of the recuperators. Dynamic models of the turbogenerators were developed and simulated with a constant power start-up strategy where the data of the designed components were integrated into the models. Results show that the turbogenerators that contain a recuperator have a startup phase characterized by high fuel consumption for 70 s mainly caused by the thermal inertia of the recuperator that causes a reduction in turbogenerators efficiencies by about 3%. Moreover, the intercooled regenerative reheated turbogenerator presented a better performance than the other turbogenerators with the highest rate of temperature increase at the inlet of the combustion chamber resulting in the lowest fuel consumption. Consequently, the intercooled regenerative reheated turbogenerator was selected as the best candidate as it had the best dynamic performance, the highest efficiency 37.9%, and net specific work 205 kJ/kg for a turbine inlet temperature of 950 • C. The developed methodology in this paper could be applied to reproduce new turbogenerator energy architectures, compare their performances, and select the best designs

Optimization of a Brayton external combustion gas-turbine system for extended range electric vehicles

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Methodology for TurboGenerator Systems Optimization in Electrified Powertrains

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Stirling machine as auxiliary power unit for range extender hybrid electric vehicles

International audienceStirling machine as auxiliary power unit for range extender hybrid electric vehicle

Brayton cycles as waste heat recovery systems on series hybrid electric vehicles

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Methodology for Fuel Saving Optimization of a Serial Hybrid Electric Vehicle using Gas Turbine as Energy Converter

International audienceSignificant research efforts have been invested in the automotive industry on hybrid-electrified powertrains inorder to reduce the passenger cars’ dependence on oil. Powertrains electrification resulted in a wide rangeof hybrid vehicle architectures. Fuel consumption of these powertrains strongly relies on the energyconverter performance, as well as on the energy management strategy deployed on-board. This paperinvestigates the potential of fuel consumption savings of a serial hybrid electric vehicle (SHEV) using a gasturbine (GT) as energy converter instead of the conventional internal combustion engine (ICE). An exergotechnoexplicit analysis is conducted to identify the best GT-system configuration. An intercooledregenerative reheat cycle is prioritized, offering higher efficiency and power density compared to otherinvestigated GT-systems. A SHEV model is developed and powertrain components are sized consideringvehicle performance criteria. Energy consumption simulations are performed on WLTP cycle using dynamicprograming as global optimal energy management strategy. A sensitivity analysis is also carried out in orderto evaluate the effect of the battery size on the fuel consumption. Results show improved fuel consumptionwith GT as auxiliary power unit (APU) compared to ICE. Moreover, GT offers other intrinsic advantages suchas reduced mass, suitable vehicle integration as well as a multi-fuel use capability. Consequently, thestudied GT-APU presents a potential for implementation on SHEVs

Fuel Consumption Saving Potential of Stirling Machine on Series Parallel Hybrid Electric Vehicle: Case of the Toyota Prius

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Exergo-technological explicit methodology for gas-turbine system optimization for series hybrid electric vehicles

International audienceSignificant research efforts have been invested in the automotive industry on hybrid-electrified powertrains in order to reduce the passenger cars’ dependence on oil. Powertrains electrification resulted in a wide range of hybrid vehicle architectures. Fuel consumption of these powertrains strongly relies on the energy converter performance, as well as on the energy management strategy deployed on-board. This paper investigates the potential of fuel consumption savings of a series hybrid electric vehicle (SHEV) using a gas turbine (GT) as energy converter instead of the conventional internal combustion engine (ICE). An exergo-technological explicit analysis is conducted to identify the best GT-system configuration. An intercooled regenerative reheat cycle is prioritized, offering higher efficiency and power density compared to other investigated GT-systems. A SHEV model is developed and powertrain components are sized considering vehicle performance criteria. Energy consumption simulations are performed on the worldwide-harmonized light vehicles test procedure (WLTP) driving cycle using dynamic programing as global optimal energy management strategy. A sensitivity analysis is also carried out in order to evaluate the impact of the battery size on the fuel consumption, for self-sustaining and plug-in hybrid SHEV configurations. Results show 22% to 25% improved fuel consumption with GT as auxiliary power unit (APU) compared to ICE. Consequently,the studied GT-APU presents a potential for implementation on SHEVs