Terms:
SAE International Journal of Alternative Powertrains
AND
7
The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Compression Ratio Control of Free Piston Linear Generator with In-Cylinder Pressure Feedforward

SAE International Journal of Alternative Powertrains

Tongji University-Lianlian Lin, Zhe Wang, Pengfei Zang
  • Journal Article
  • 08-07-02-0008
Published 2018-06-28 by SAE International in United States
The free piston linear generator (FPLG) is a novel machine that functions as an Auxiliary Power Unit (APU) for hybrid electric vehicles, which contains two opposed free piston engines and one linear generator between them. FPLG has attracted extensive interest for its potential advantages in terms of high power density and multi-fuel flexibility. The guarantee of FPLG generating electricity steadily and efficiently is the high controllability of compression ratio. In this article, a control-oriented discrete-time model was established based on Otto cycle. Since the fluctuation of in-cylinder pressure caused by instable fuel injection mass and combustion process is the main disturbance, a composite controller is designed to precisely control the compression ratio of FPLG. The composite controller is made up of a feedforward controller and a feedback tracking controller. Finally, the control performance of the composite controller and a general proportional-integral (PI) controller was compared by simulation. The simulation results indicate that the composite controller shows better performance in transient process when fuel injection mass or reference compression ratio changes suddenly. Furthermore, the standard deviation…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Efficient Supercapacitors Based on Co9S8/Graphene Composites for Electric Vehicles

SAE International Journal of Alternative Powertrains

JIlin University-Yu Yang, Fangwu Ma, Wei Han, Junzhi Li, Junming Cao, Ying Zhao, Liang Wu
  • Journal Article
  • 2018-01-0440
Published 2018-04-03 by SAE International in United States
Nowadays, SC is recognized as a key element of hybrid energy storage system in modern energy supply chain for electric vehicles (EVs). Co9S8 as a promising electrode material attracts much attention for supercapacitor owing to its superior electrochemical capacity. However, its poor stability and electronic conductivity, which result in inferior cycling performance and rate capability, have seriously limited the practical application of Co9O8 in supercapacitors.In this article, Co9S8 nanoparticles were embedded in reduced graphene oxide (rGO) via a simple anneal approach as high efficient and stable electrodes for SCs. The Co9S8/rGO composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The Co9S8 nanoparticles were inserted tightly between the rGO layers due to strong intermolecular forces, preventing the cluster in reduction process of rGO from graphene oxide (GO). The rGO provides the conductive network for Co9S8 and shortens the ion diffusion paths, improving rate performance and enhancing the stability of the electrode material. The as-prepared Co9S8/rGO takes full advantages of high capacitance performance of Co9S8 nanoparticles and excellent conductivity…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Electric Powertrain for CLARITY PLUG-IN HYBRID

SAE International Journal of Alternative Powertrains

Honda R&D Co., Ltd.-Tomoya Yamagishi, Takashi Ishikura
  • Journal Article
  • 2018-01-0415
Published 2018-04-03 by SAE International in United States
Honda has developed the 2018 model CLARITY PLUG-IN HYBRID. Honda’s new plug-in hybrid is a midsize sedan and shares a body platform with the CLARITY FUEL CELL and the CLARITY ELECTRIC. The vehicle’s electric powertrain boosts driving performance as an electric vehicle (EV) over Honda’s previous plug-in hybrid.The CLARITY PLUG-IN HYBRID’s electric powertrain consists of a traction motor and generator built into the transmission, a Power Control Unit (PCU) positioned above the transmission, an Intelligent Power Unit (IPU) fitted under the floor, and an onboard charger fitted below the rear trunk.The PCU integrates an inverter that drives the traction motor, an inverter that drives the generator, and a DC-DC converter to boost battery voltage (referred to as a “Voltage Control Unit (VCU)” below). The VCU employs an interleaved circuit configuration and a coupled inductor and realizes approximately three times the rated continuous power and approximately three times the power density of a standard unit employed in a hybrid vehicle.The IPU contains 17 kWh high-capacity battery modules and a 12 V DC-DC converter. A coolant-cooling method…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Charger Sizing for Long-Range Battery Electric Vehicles

SAE International Journal of Alternative Powertrains

Ford Electric Vehicle-Daniel Kok
Ford Motor Co., Ltd.-Jaswant Dhillon, N Khalid Ahmed, Kevin Rhodes
  • Journal Article
  • 2018-01-0427
Published 2018-04-03 by SAE International in United States
The falling cost of lithium ion batteries combined with an ongoing need to reduce greenhouse gas emissions is driving the proliferation of affordable long-range battery electric vehicles (BEVs). However, an inherent challenge with longer-range BEVs is the increased time required to fully charge the battery using standard 120/240 V AC power outlets. One approach to address this issue involves moving to higher power onboard AC chargers; however, household and utility wiring may not allow for the full capability of these higher power chargers. This study explores the typical time available for vehicle charging during an overnight stop based on real-world customer “MyFord Mobile” (MFM) data collected from Ford electrified vehicles. Through this approach, the available overnight time for recharging and required energy to be added to the battery are evaluated under the influence of typical daily driving distances, extreme ambient temperatures, and value charging time windows.
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Standardized Battery Pack for Next-Generation PHEVs in Considering the Effect of External Pressure on Lithium-Ion Pouch Cells

SAE International Journal of Alternative Powertrains

Hyundai Motor Company-Yong Hwan Choi, Hae Kyu Lim, Jeong-Hun Seo, Woo Jin Shin, Jae Hoon Choi, Jin Ho Park
  • Journal Article
  • 2018-01-0439
Published 2018-04-03 by SAE International in United States
The performance and marketability of eco-friendly vehicles highly depend on their high-voltage battery system. Lithium-ion pouch cells have advantages of high energy density and cost-effectiveness than other types of batteries. However, due to their low mechanical stability, their characteristics are strongly influenced by external conditions. Especially, external pressure on pouch cell is a crucial factor for the performance, life cycle, and structural safety of battery pack. Therefore, optimizing pressure level has been a critical consideration in designing battery pack structures for lithium-ion pouch cell. In this work, we developed an optimized structure of the battery module and pack to apply appropriate pressure on pouch cells. They also include a standardization strategy to meet the varied demand in capacity and power for automotive application. The footprint of cell is standardized, and the thickness of cell is varied according to the capacity of a cell which is determined by the number of electrodes and thickness of active materials. The module and pack structures comprise standard and unique parts. The standard parts hold a cell to ensure structural…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Discussion on Charging Control Strategy for Power Battery at Low Temperatures

SAE International Journal of Alternative Powertrains

Dongfeng Motor Corporation-Liu Xiaojun, Yu Jinpeng, Yang Xia, Wu Daoming
The Kanto Science and Technology-Jie Zhu
  • Journal Article
  • 08-07-01-0004
Published 2017-10-08 by SAE International in United States
In the case of electric vehicles, due to the charging current limitation of lithium battery at low temperatures (below -20°C), it has been proposed to heat the battery pack up to a suitable temperature range before charging through a liquid-heating plate with PTC. However, at a low state of charge (SOC), there is a question which one could take the place of battery pack to supply power for PTC when heating. So that off-board charger (OFC) has been considered to supply power for PTC in this article. In order to control the current charging into the battery pack as less as possible at low temperatures, three control schemes of battery management system (BMS) are proposed and compared. Scheme 1: BMS controls the value of charging current request close to the working current of PTC. Scheme 2: BMS controls the value of charging voltage request to reach a state of relative balance. Scheme 3: BMS disconnects the pack from the charger and keeps the connection between PTC and charger. The functions of the three schemes above…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Electric Vehicle with Multi-Speed Transmission: A Review on Performances and Complexities

SAE International Journal of Alternative Powertrains

Swinburne University of Technology, Australia-Md Ragib Ahssan, Mehran Motamed Ektesabi, Saman Asghari Gorji
  • Journal Article
  • 08-07-02-0011
Published 2018-12-04 by SAE International in United States
Electric vehicles (EVs) with multi-speed transmission offer improved performances compared to those with single speed transmission system in terms of top speed, fast acceleration, or gradeability along with driving range. In this study, relevant literature is extensively analyzed to explore the performances and associated complexities with multi-speed automatic manual/mechanical transmission (AMT) system in EVs. In EV powertrain, the only torque generator component is electric motor, which is not equally efficient throughout wider speed range. To the other end, vehicles need to run at different speeds in diverse driving conditions. The study shows that multi-speed transmission system enables efficient operation of electric motor by choosing an appropriate gear at different driving torque-speed demands and thus contributes to achieve desired vehicle performances at minimum energy consumption. To demonstrate the differences, both dynamic and economic performances with multi-gear system and single speed system are compared, and the results of various techniques are presented in the form of tables and bar charts. A quantitative analysis is also conducted to show the performance improvement achievable by employing multi-speed transmission concept…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Combined Battery Design Optimization and Energy Management of a Series Hybrid Military Truck

SAE International Journal of Alternative Powertrains

Clemson University, USA-Zifan Liu, Abdullah-Al Mamun Mamun
Stanford University, USA-Simona Onori
  • Journal Article
  • 08-07-02-0010
Published 2018-10-31 by SAE International in United States
This article investigates the fuel savings potential of a series hybrid military truck using a simultaneous battery pack design and powertrain supervisory control optimization algorithm. The design optimization refers to the sizing of the lithium-ion battery pack in the hybrid configuration. The powertrain supervisory control optimization determines the most efficient way to split the power demand between the battery pack and the engine. Despite the available design and control optimization techniques, a generalized mathematical formulation and solution approach for combined design and control optimization is still missing in the literature. This article intends to fill that void by proposing a unified framework to simultaneously optimize both the battery pack size and power split control sequence. This is achieved through a combination of genetic algorithm (GA) and Pontryagin’s minimum principle (PMP) where the design parameters are integrated into the Hamiltonian function. As GA and PMP are global optimization methodologies under suitable conditions, the solution can be considered as a benchmark for the application under study. Five military drive cycles are used to evaluate the proposed approach.…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of a Catalytic Converter Cool-Down Model to Investigate Intermittent Engine Operation in HEVs

SAE International Journal of Alternative Powertrains

The University of Alabama, USA-Karissa Young, Ryan Jones, A.J. Hamley, Josh Stoddard, Travis Foust, Paul Puzinauskas, Hwan-Sik Yoon
  • Journal Article
  • 08-07-02-0009
Published 2018-10-29 by SAE International in United States
Catalytic converters, a primary component in most automotive emissions control systems, do not function well until they are heated substantially above ambient temperature. As the primary energy for catalyst heating comes from engine exhaust gases, plug-in hybrid electric vehicles (PHEVs) that have the potential for short and infrequent use of their onboard engine may have limited energy available for catalytic converter heating. This article presents a comparison of multiple hybrid supervisory control strategies to determine the ability to avoid engine cold starts during a blended charge-depleting propulsion mode. Full vehicle and catalytic converter simulations are performed in parallel with engine dynamometer testing in order to examine catalyst temperature variations during the course of the US06 City drive cycle. Emissions and energy consumption (E&EC) calculations are also performed to determine the effective number of engine starts during the drive cycle.
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Multi-Attribute, System-Level Design Process for Automotive Powertrain Electric Drives: An Integrated Approach

SAE International Journal of Alternative Powertrains

Siemens Industry Software-Cassio T. Faria
Technical University of Cluj-Napoca (TUCN)-Sebastian Ciceo, Claudia Martis
  • Journal Article
  • 08-07-02-0007
Published 2018-06-05 by SAE International in United States
This article presents an electric drive powertrain design and virtual integration methodology in the context of electric vehicle systems. In the first stage, using the Model-Based System Engineering paradigm, the electric vehicle performance requirements are translated into electric drive target specifications using a system-level vehicle model. Subsequently, a functional electric drive subsystem-level model is developed based on magnetic co-energy and iron losses data obtained from a reference electric machine design. The functional electric drive model is scaled in order to meet the requested specifications, and it is coupled with different 1D (i.e. lumped-parameter) multi-physics sub-models that are later integrated into the electric vehicle system-level model. At the electric drive level the torque ripple and Noise, Vibration and Harshness characteristics are analyzed. At the vehicle level the energy consumption, thermal behavior, and mechanical performances are determined with reduced computational time. The proposed approach allows for early assessment of multiple attributes and enables designers to make decisions supported by accurate system-level simulations.
This content contains downloadable datasets
Annotation ability available