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SAE International Journal of Alternative Powertrains
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Intelligent Alternator Employment To Reduce Co2 Emission and to Improve Engine Performance

SAE International Journal of Alternative Powertrains

Fiat Powertrain SPA-Iolanda Montalto, Domenico Tavella lng, Ferdinando De Cristofaro
Università della Calabria-Alessandro Casavola PhD
  • Journal Article
  • 2011-01-2444
Published 2012-06-15 by SAE International in United States
In modern internal combustion engines a greater reduction of CO₂ emissions is required in order to significantly reduce fuel consumption and minimize the emissions of polluting gases, allowing them to fall within the strict limits set by current regulations. In a conventional engine control system, it is not possible to optimize the efficiency of the alternator in terms of emissions and fuel consumption, due to a constant voltage which is imposed and is not modifiable. On the contrary, in a system capable of controlling the voltage of the alternator, referring to such an alternator as "smart" hereafter, it would be possible to optimize its efficiency as a function of the vehicle/engine working points. This system requires first and foremost a communication protocol between the alternator and engine control unit, and a special sensor that gets data on the charging status of the battery.In this chapter a management strategy is proposed for regulating the alternator regulation voltage in order to maximize its efficiency on the basis of the engine and vehicle conditions. This is done by…
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Methodology for Assessment of Alternative Hybrid Electric Vehicle Powertrain System Architectures

SAE International Journal of Alternative Powertrains

Ford Motor Co.-Alexander T. Zaremba, Ciro Soto, Mark Jennings
  • Journal Article
  • 2012-01-1010
Published 2012-04-16 by SAE International in United States
Hybrid electric vehicle (HEV) systems offer significant improvements in vehicle fuel economy and reductions in vehicle generated greenhouse gas emissions. The widely accepted power-split HEV system configuration couples together an internal combustion engine with two electric machines (a motor and a generator) through a planetary gear set. This paper describes a methodology for analysis and optimization of alternative HEV power-split configurations defined by alternative connections between power sources and transaxle. The alternative configurations are identified by a matrix of kinematic equations for connected power sources. Based on the universal kinematic matrix, a generic method for automatically formulating dynamic models is developed. Screening and optimization of alternative configurations involves verification of a set of design requirements which reflect: vehicle continuous operation, e.g. grade test; and vehicle dynamic operation such as acceleration and drivability. Only the former are consider in this paper. The method automatically defines a design parameter space for each configuration which eventually would allow configuration evaluation and optimization, e.g. sizing of power sources or optimization of transaxle gear ratios.
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Temperature Characteristics of a Hybrid Electric Vehicle Fire

SAE International Journal of Alternative Powertrains

National Traffic Safety & Enviro Lab.-Hideki Matsumura, Shinichiro Itoh, Kazuo Matsushima, Takeo okada
  • Journal Article
  • 2012-01-0982
Published 2012-04-16 by SAE International in United States
Recently, vehicles with high capacity traction batteries for driving such as Ni-MH, lithium-ion have come to be produced in the world. However, the damage has not been clarified in the case of these vehicles fire by a traffic accident or arson. In particular, lithium-ion cells in high temperature environment may cause a thermal runaway which emits smoke or flare. Therefore, it is necessary to examine what kinds of phenomena occur when a vehicle with a lithium-ion battery catches fire. In this paper, the authors studied the situation and temperature characteristics of a hybrid electric vehicle fire to investigate the temperature input to a lithium-ion battery on a vehicle. We assumed an accident that gasoline leaking from other vehicle would be spread under a vehicle and ignited. In a vehicle fire test, gasoline was spread under a hybrid electric vehicle without the traction battery instead of a vehicle with lithium-ion battery, and ignited. Thermocouple sensors were installed inside and under the vehicle. During the test, the situation of the vehicle fire was recorded by photos and…
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PEFC Performance Improvement Methodology for Vehicle Applications

SAE International Journal of Alternative Powertrains

Nippon Soken, Inc.-Masahiro Shiozawa
Toyota Motor Corporation-Shigetaka Hamada, Masaaki Kondo, Sogo Goto
  • Journal Article
  • 2012-01-1232
Published 2012-04-16 by SAE International in United States
For over a decade and a half, Toyota Motor Corporation has been developing fuel cell vehicles (FCVs) and is continuing various approaches to enable mass production. This study used new methods to quantitatively observe some of the mass transfer phenomena in the reaction field, such as oxygen transport, water drainage, and electronic conductivity. The obtained results are applicable to the design requirements of ideal reaction fields, and have the potential to assist to reduce the size of the fuel cell.
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Development of System Control for Rapid Warm-up Operation of Fuel Cell

SAE International Journal of Alternative Powertrains

Toyota Motor Corporation-Yoshiaki Naganuma, Kota Manabe, Hiroyuki Imanishi, Yasuhiro Nonobe
  • Journal Article
  • 2012-01-1230
Published 2012-04-16 by SAE International in United States
Cold weather operation has been a major issue for fuel cell hybrid vehicles (FCHV). To counteract the effects of low temperatures on FCHV operation, an approach for rapid warm-up operation based on concentration overvoltage increase and conversion efficiency decrease by limiting oxygen or hydrogen supply was adopted. In order to suppress increases in exhaust hydrogen concentration due to pumping hydrogen during rapid warm-up, dilution control using bypass air and reduction of concentration overvoltage by a minimum voltage guard were implemented. These approaches effectively control waste heat generation and suppress exhaust hydrogen concentrations during cold start and warm-up. These developments were incorporated into the 2008 Toyota FCHV-adv and it was confirmed that the rapid warm-up operation strategy allowed the FCHV-adv to be successfully and repeatedly started at -30°C.
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Inverter Dead-Time Compensation up to the Field Weakening Region with Respect to Low Sampling Rates

SAE International Journal of Alternative Powertrains

University of Stuttgart-Hans-Christian Reuss
ZF Lenksysteme GmbH-Eugen Sworowski, Thomas Pötzl
  • Journal Article
  • 2012-01-0500
Published 2012-04-16 by SAE International in United States
This report presents a new compensation method for distortions related to dead time, caused by B6-inverters with pulse-width-modulated output voltages. In spite of low sampling rates, the new method of compensation is effective at all ranges of rotation speed up to the field weakening region. No additional hardware is required for its implementation. The effectiveness of the new method has been shown experimentally. A description of the relevant distortions is given first to provide a basis for the development. This considers the field weakening region, and offers an illustrative method of quantifying the distortions. It is also shown that the use of compensation methods that do not take the sampling time into account leads to additional distortions. It is even possible that they exceed the distortions in an equivalent system without compensation.
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Thermal Analysis of a Li-ion Battery System with Indirect Liquid Cooling Using Finite Element Analysis Approach

SAE International Journal of Alternative Powertrains

AVL Powertrain Engineering Inc-Kim Yeow, Ho Teng, Marina Thelliez, Eugene Tan
  • Journal Article
  • 2012-01-0331
Published 2012-04-16 by SAE International in United States
The performance and life of Li-ion battery packs for electric vehicle (EV), hybrid electrical vehicle (HEV), and plug-in hybrid electrical vehicle (PHEV) applications are influenced significantly by battery operation temperatures. Thermal management of a battery pack is one of the main factors to be considered in the pack design, especially for those with indirect air or indirect liquid cooling since the cooling medium is not in contact with the battery cells. In this paper, thermal behavior of Li-ion pouch cells in a battery system for PHEV applications is studied. The battery system is cooled indirectly with liquid through aluminum cooling fins in contact with each cell and a liquid cooled cold plate for each module in the battery pack. The aluminum cooling fins function as a thermal bridge between the cells and the cold plate. Cell temperature distributions are simulated using a finite element analysis approach under cell utilizations corresponding to PHEV applications. Both single cold plate cooling and dual cold plate cooling were analyzed. Influences of the cold plate surface temperature gradients on the…
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Centralized Torque Controller for a Nonminimum Phase Phenomenon in a Powersplit HEV

SAE International Journal of Alternative Powertrains

Ford Motor Co.-Qing Wang, Fazal Syed, Ryan McGee, Ming Kuang, Anthony Phillips
  • Journal Article
  • 2012-01-1026
Published 2012-04-16 by SAE International in United States
Torque controls for the engine and electric motors in a Powersplit HEV are keys to the success of balancing fuel economy, driveability, and battery power control. The electric variable transmission (EVT) offers an opportunity to let the engine operate at system-optimal fuel efficient points independently of any load. Existing work shows such a benefit can be realized through a decentralized control structure that translates the driver inputs to independent engine torque and speed control. However, our study shows that the decentralized control structures have a fundamental limitation that arises from the nonminimum phase (NMP) zero in the transfer function from the driver power command to the generator torque change rate, and thus not only is it difficult to obtain smooth generator torque but also it can cause violations on battery power limits during transients. Additionally, it adversely affects the driveability due to the generator torque transients reflected at the ring gear. This study investigated a novel centralized torque controller to enhance smart coordination between the engine and generator. We first analyzed the theoretical limitations of…
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Thermal Analysis of a High-Power Lithium-Ion Battery System with Indirect Air Cooling

SAE International Journal of Alternative Powertrains

AVL Powertrain Engineering Inc.-Ho Teng
  • Journal Article
  • 2012-01-0333
Published 2012-04-16 by SAE International in United States
Thermal behavior of a lithium-ion (Li-ion) battery module for hybrid electrical vehicle (HEV) applications is analyzed in this study. The module is stacked with 12 high-power pouch Li-ion battery cells. The cells are cooled indirectly with air through aluminum fins sandwiched between each two cells in the module, and each of the cooling fins has an extended cooling surface exposed in the cooling air flow channel. The cell temperatures are analyzed using a quasi-dimensional model under both the transient module load in a user-defined cycle for the battery system utilizations and an equivalent continuous load in the cycle. The cell thermal behavior is evaluated with the volume averaged cell temperature and the cell heat transfer is characterized with resistances for all thermal links in the heat transfer path from the cell to the cooling air. Simulations results are compared with measurements. Good agreement is observed between the simulated and measured cell temperatures. The results of this analysis demonstrate that the method developed in this study is reliable for characterizing thermal behavior of the Li-ion battery…
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Cabin Heating and Windshield Defrosting for Extended Range Electric, Pure Electric, & Plug-in Hybrid Vehicles

SAE International Journal of Alternative Powertrains

General Motors Company-Mark Nemesh, Matthew Martinchick, Sam Ibri
  • Journal Article
  • 2012-01-0121
Published 2012-04-16 by SAE International in United States
Conventional HVAC systems adjust the position of a temperature door, to achieve a required air temperature discharged into the passenger compartment. Such systems are based upon the fact that a conventional (non-hybrid) vehicle's engine coolant temperature is controlled to a somewhat constant temperature, using an engine thermostat. Coolant flow rate through the cabin heater core varies as the engine speed changes.EREVs (Extended Range Electric Vehicles) & PHEVs (Plug-In Hybrid Electric Vehicles) have two key vehicle requirements: maximize EV (Electric Vehicle) range and maximize fuel economy when the engine is operating. In EV mode, there is no engine heat rejection and battery pack energy is consumed in order to provide heat to the passenger compartment, for windshield defrost/defog and occupant comfort. Energy consumption for cabin heating must be optimized, if one is to optimize vehicle EV range.A new heating system has been developed for providing cabin heating and windshield defrost for such new vehicle propulsion systems, which includes a HV (High-voltage) PTC (positive temperature coefficient) coolant heater, electric coolant pump, and coolant control valve.
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