EPE Association: EPE 2017 - LS5f: Electric Vehicle Propulsion Systems and their Energy Storage

EPE 2017 - LS5f: Electric Vehicle Propulsion Systems and their Energy Storage
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 08: e-Mobility > EPE 2017 - LS5f: Electric Vehicle Propulsion Systems and their Energy Storage

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   Adopting MOSFET Multilevel Inverters to Improve the Partial Load Efficiency of Electric Vehicles
By Fengqi CHANG [View]
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Abstract: The efficiency of the electric powertrain has a direct influence on the cost and range of electricvehicles, which are the two key factors hindering the public acceptance of electric vehicles (EVs).Inverters, as an important component of the electric powertrain, have a high efficiency at full load, butan unsatisfying performance at partial load due to the bipolar characteristics of IGBT. To improve thepartial load efficiency, this paper proposes to use multilevel inverters composed of low voltageMOSFETs to replace six-pack IGBT inverters in EVs. The proposal is justified by a detailed analysisbased on a BMW i3 vehicle model and an accurate model of semiconductor losses in ANSYSSimplorer. Moreover, a cost comparison proved that the multilevel inverter using common low voltageMOSFETs is the best option among all the solutions considering the current costs of the components.

   Coupled Electric and Thermal Batteries Models using Energetic Macroscopic Representation (EMR) for Range Estimation in Electric Vehicles
By Alain BOUSCAYROL [View]
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Abstract: Electric models of battery have to take into account the effect of temperature for the state-of-chargeestimation. As a matter of fact, at low temperature the driving range of the vehicle can beoverestimated up to more than 20\% with electric only models. We propose to couple thermal andelectric battery models for improving the range estimation.

   How to choose drive's rated power in electrified urban transport_
By Mikolaj BARTLOMIEJCZYK [View]
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Abstract: Selection of drive's rated power influences not only vehicle's dynamics, but also its energy efficiency. Mentioned above approach requires a multiphysical model, which covers both mechanical and electrical phenomena. This paper discusses how selection of traction drive's rated power influences vehicle energy consumption on example of a trolleybus. A complex mathematical model was developed in Matlab/Simulink to describe the multiphisical dependencies. Several driving scenarios were proposed to compare the energy consumption between trolleybuses equipped with medium- and high-power electric drive in different conditions. Numerical investigations reveal the possibility of gaining substantial energy savings using of the high-power drive.

   Model predictive control based balancing strategy for series-connected lithium-ion battery packs
By Linfeng ZHENG [View]
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Abstract: For reducing the inconsistent state of charges (SOCs) of lithium-ion battery cells and making the full use of battery packs, effective battery balancing technology should be in place for battery management systems. Since aged battery packs usually suffer from not only non-uniform cell SOCs and voltages but also non-uniform cell capacities, it is more challenging to balance an aged battery pack than a new one. This paper proposes a model predictive control (MPC) based balancing strategy to fully charge battery packs under such inconsistent conditions, especially for aged battery packs. The algorithm of the proposed strategy for computing the required average balancing current and the predicted balancing current for each cell is presented, followed by employing a minimum cost function value between these two currents to control the operation model of the equalizer for each cell. The simulation results verify the effectiveness of the proposed approach. Compared with the conventional average SOC strategy, the proposed MPC based strategy can effectively avoid over-equalization during the balancing process, thus reducing balancing energy consumption.

EPE 2017 - LS5f: Electric Vehicle Propulsion Systems and their Energy Storage
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 08: e-Mobility > EPE 2017 - LS5f: Electric Vehicle Propulsion Systems and their Energy Storage
	[return to parent folder]

	Adopting MOSFET Multilevel Inverters to Improve the Partial Load Efficiency of Electric Vehicles By Fengqi CHANG	[View] [Download]
Abstract: The efficiency of the electric powertrain has a direct influence on the cost and range of electricvehicles, which are the two key factors hindering the public acceptance of electric vehicles (EVs).Inverters, as an important component of the electric powertrain, have a high efficiency at full load, butan unsatisfying performance at partial load due to the bipolar characteristics of IGBT. To improve thepartial load efficiency, this paper proposes to use multilevel inverters composed of low voltageMOSFETs to replace six-pack IGBT inverters in EVs. The proposal is justified by a detailed analysisbased on a BMW i3 vehicle model and an accurate model of semiconductor losses in ANSYSSimplorer. Moreover, a cost comparison proved that the multilevel inverter using common low voltageMOSFETs is the best option among all the solutions considering the current costs of the components.

	Coupled Electric and Thermal Batteries Models using Energetic Macroscopic Representation (EMR) for Range Estimation in Electric Vehicles By Alain BOUSCAYROL	[View] [Download]
Abstract: Electric models of battery have to take into account the effect of temperature for the state-of-chargeestimation. As a matter of fact, at low temperature the driving range of the vehicle can beoverestimated up to more than 20\% with electric only models. We propose to couple thermal andelectric battery models for improving the range estimation.

	How to choose drive's rated power in electrified urban transport_ By Mikolaj BARTLOMIEJCZYK	[View] [Download]
Abstract: Selection of drive's rated power influences not only vehicle's dynamics, but also its energy efficiency. Mentioned above approach requires a multiphysical model, which covers both mechanical and electrical phenomena. This paper discusses how selection of traction drive's rated power influences vehicle energy consumption on example of a trolleybus. A complex mathematical model was developed in Matlab/Simulink to describe the multiphisical dependencies. Several driving scenarios were proposed to compare the energy consumption between trolleybuses equipped with medium- and high-power electric drive in different conditions. Numerical investigations reveal the possibility of gaining substantial energy savings using of the high-power drive.

	Model predictive control based balancing strategy for series-connected lithium-ion battery packs By Linfeng ZHENG	[View] [Download]
Abstract: For reducing the inconsistent state of charges (SOCs) of lithium-ion battery cells and making the full use of battery packs, effective battery balancing technology should be in place for battery management systems. Since aged battery packs usually suffer from not only non-uniform cell SOCs and voltages but also non-uniform cell capacities, it is more challenging to balance an aged battery pack than a new one. This paper proposes a model predictive control (MPC) based balancing strategy to fully charge battery packs under such inconsistent conditions, especially for aged battery packs. The algorithm of the proposed strategy for computing the required average balancing current and the predicted balancing current for each cell is presented, followed by employing a minimum cost function value between these two currents to control the operation model of the equalizer for each cell. The simulation results verify the effectiveness of the proposed approach. Compared with the conventional average SOC strategy, the proposed MPC based strategy can effectively avoid over-equalization during the balancing process, thus reducing balancing energy consumption.