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Viewing 241 to 270 of 16536
2017-03-28
Journal Article
2017-01-1215
Peter Haussmann, Joachim Melbert
Abstract Battery safety is the most critical requirement for the energy storage systems in hybrid and electric vehicles. The allowable battery temperature is limited with respect to the battery chemistry in order to avoid the risk of thermal runaway. Battery temperature monitoring is already implemented in electric vehicles, however only cell surface temperature can be measured at reasonable cost using conventional sensors. The internal cell temperature may exceed the surface temperature significantly at high current due to the finite internal electrical and thermal cell resistance. In this work, a novel approach for internal cell temperature measurement is proposed applying on board impedance spectroscopy. The method considers the temperature coefficient of the complex internal cell impedance. It can be observed by current and voltage measurements as usually performed by standard battery management systems.
2017-03-28
Journal Article
2017-01-1216
Edward C. Fontana, Rick Barnett, Robert Catalano, James Harvey, Jiacheng He, George Ottinger, John Steel
Abstract Electric cars can help cities solve air quality problems, but drivers who live in apartments have no convenient way to charge daily, absent the well-controlled private garages where most electric vehicles (EVs) are currently charged each night. Environmentally robust, hands-free, inductive chargers would be ideal, but energy efficiency suffers. We asked whether the precise parking alignment provided by self-driving cars could be used to provide convenient inductive charging with improved charging efficiencies. To answer this question, we split an inductor-inductor-capacitor (LLC) battery charger at the middle of the isolation transformer. The power factor correction, tank elements, and transformer primary windings are stationary, while the transformer secondary, rectifiers, and battery control logic are on the vehicle. The transformer is assembled each time the EV parks.
2017-03-28
Technical Paper
2017-01-1217
Jiangong Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai
Abstract An alternating current (AC) heating method for a NMC lithium-ion battery with 8Ah capacity is proposed. The effects of excitation frequency, current amplitudes, and voltage limit condition on the temperature evolution are investigated experimentally. Current amplitudes are set to 24A(3C), 40(5C), and 64A(8C), and excitation frequencies are set to 300Hz, 100Hz, 30Hz, 10Hz, 5Hz, and 1Hz respectively. The voltage limitations are necessary to protect cells from overcharge and over-discharge. Therefore the voltage limit condition (4.2V/2.75V, 4.3V/2.65V, and 4.4V/2.55V) are also considered in depth to verify the feasibility of the AC heating method. The temperature rises prominently as the current increases, and the decrement of frequencies also lead to the obvious growth of battery temperature. The battery obtain the maximum temperature rise at 64A and 1Hz, which takes 1800s to heat up the battery from -25°C to 18°C.
2017-03-28
Journal Article
2017-01-1218
XINCHEN ZHAO, Yalan Bi, Song-Yul Choe
Abstract We propose a reduced order model (ROM) for LFP/graphite cells derived from the electrochemical thermal principles that considers degradation effects and validated against experimental data obtained from a large format pouch type LFP/graphite cell whose nominal capacity is 20Ah. The characteristics of the two-phase transition and path dependence were taken into account in the ROM using a shrinking-core model with a moving interface that presents lithium rich and deficient phase. Different currents (0.1/1/3/4C) were applied to fresh cells at different ambient temperatures (25/35/45°C). Comparison between simulated results of the ROM and the collected experimental data shows a good match. The path dependence was also analyzed experimentally. For degradation model, side reaction is treated as the predominant cause of degradation of cells, which are affected by the operating conditions, such as temperature and SOC cycling range.
2017-03-28
Technical Paper
2017-01-1219
Steven G. Rinaldo, Zhihong Jin, Perry Wyatt
Abstract Validation of the State-Of-Function (SOF) algorithm and associated cell models are critical for battery management as they are responsible for optimal pack power utilization as well as safety protection and life. The SOF accomplishes this optimization task by communicating pack level operation limits related to power, current, voltage and temperature. These operation limits are, in some cases, estimated via parameters and equations derived from cell models. Correspondingly, any errors within the cell models will propagate into the model-dependent SOF limits. Understanding the source of errors and thus finding areas for improvement requires a visualization-based SOF validation strategy.
2017-03-28
Technical Paper
2017-01-1222
Jeongwon Rho, Jeongbin Yim, Daewoong Han, Gubae Kang, Seongyeop Lim
Abstract The current sensor for motor control is one of the main components in inverters for eco-friendly vehicles. Recently, as the higher performance of torque control has become required, the current sensor measurement error and accuracy of motor controls have become more significant. Since the response time of the sensor affects the motor output power, the response delay of the sensor causes measurement errors of the current. Accordingly, the voltage vector changes, and a motor output power deviation occurs. In the case of the large response delay of the sensor, as motor speed increases, then difference between motoring and generating output power becomes larger and larger. This results in the deterioration of power performance in high-speed operation. The deviation of the voltage vector magnitude is the main cause of motor output power deviation and imbalance through the simulation.
2017-03-28
Technical Paper
2017-01-1224
Ryota Kitamoto, Shinnosuke Sato, Hiromichi Nakamura, Atsushi Amano
Abstract A new fuel cell voltage control unit (FCVCU) has been developed for a new fuel cell vehicle (FCV). In order to simultaneously reduce the electric powertrain size and increase the driving motor power, the FCVCU is needed to boost the voltage supplied from the fuel cell (FC) stack to the driving motor. The FCVCU circuit configuration has four single-phase chopper circuits arranged in parallel to form a 4-phase interleaved circuit. The intelligent power module (IPM) is a full SiC IPM, the first known use to date in a mass production vehicle, and efficiency has been enhanced by making use of the effects of the increased frequency to reduce both the size of the unit and the loss from passive parts. In addition, a coupled inductor was used to reduce the inductor size. As a result, the inductor volume per unit power was reduced approximately 30% compared to the previous VCU inductor.
2017-03-28
Technical Paper
2017-01-1233
Mohamed A. Elshaer, Allan Gale, Chingchi Chen
Abstract Vehicle safety is of paramount importance when it comes to plugging the vehicle into the electric utility grid. The impact of high voltage ground fault has been neglected or, if not, addressed by guidelines extracted from general practices, written in international standards. The agile accretion in Electric Vehicle (EV) development deems an exhaustive study on safety risks pertaining to fault occurrence. While vehicle electrification offers a vital solution to oil scarcity, it is essential that the fast development of the number of electric vehicles on the road does not compromise safety. Meanwhile, the link between technology and demands of society must be governed by vehicle safety. In this paper, a comprehensive study on high voltage (HV) fault conditions occurring in an EV will be conducted. In the next decade, EVs are expected to be prevalent worldwide. Ground fault characteristics are significantly dependent on the earthing system.
2017-03-28
Technical Paper
2017-01-1236
Shuitao Yang, Lihua Chen, Mohammed Khorshed Alam, Fan Xu, Yan Zhou
Abstract A hybrid electric vehicle (HEV) can utilize the electromechanical path to optimize the ICE operation and implement the regenerative brake, the fuel economy of a vehicle therefore gets improved significantly. Bi-directional Boost converter is usually used in an electric drive system to boost the high voltage (HV) battery voltage to a higher dc-link voltage. The main advantages for a system with Boost converter is that the traction inverter is de-coupled from battery voltage variations causing it to be over-sized. When designing this Boost converter, the switching frequency is a key parameter for the converter design. Higher switching frequency will lead to higher switching loss of power device (IGBT +diode), moreover, it has significant impact on inductor ripple current, HV battery ripple current and input capacitor current. Therefore, the switching frequency is one of the most important parameters for the design and selection of both active and passive components.
2017-03-28
Journal Article
2017-01-1243
Yan Zhou, Lihua Chen, Shuitao Yang, Fan Xu, Mohammed Khorshed Alam
Abstract The IGBTs are dominantly used in traction inverters for automotive applications. Because the Si-based device technology is being pushed to its theoretical performance limit in such applications during recent years, the gate driver design is playing a more prominent role to further improve the traction inverter loss performance. The conventional gate driver design in traction inverter application needs to consider worst case scenarios which adversely limit the semiconductor devices' switching speed in its most frequent operation regions. Specifically, when selecting the gate resistors, the IGBT peak surge voltage induced by fast di/dt and stray inductance must be limited below the device rated voltage rating under any conditions. The worst cases considered include both highest dc bus voltage and maximum load current. However, the traction inverter operates mainly in low current regions and at bus voltage much lower than the worst case voltage.
2017-03-28
Technical Paper
2017-01-1240
Koki Matsushita
Abstract For the purpose of improving vehicle fuel efficiency, it is necessary to reduce energy loss in the alternator. We have lowered the resistance of the rectifying device and connecting components, and control the rectifying device with an IC to reduce rectification loss. For the package design, we have changed the structure of the part on which the rectifying device is mounted into a high heat dissipation type. The new structure has enabled optimizing the size of the rectifying device, resulting in the reduction of size of the package. In addition, the rectifying device is mounted using a new soldering material and a new process, which has improved the reliability of the connection. Moreover, since the alternator has introduced a new system, the controller IC has a function for preventing malfunction of the rectifying device and a function for detecting abnormalities, in order to ensure safety.
2017-03-28
Technical Paper
2017-01-1241
Wei Zhang, Rajesh Malhan
Abstract Wireless power transfer (WPT) technology has started to be applied in charging electrical vehicles (EV). EV models with built-in wireless charging capability is expected to be available from several major automakers in the next few years. Meanwhile, problems associated with the massive adoption of automobiles require new format of vehicles, especially the form with compact size and electric power. An inductively charged autonomous bicycle (iCab) is proposed, which has both the automotive driving and wireless charging features. It is designed to be compatible with an EV wireless charger. The wireless charging interoperability issue of the single transmitting coil capable to charge both the EV and iCab is studied in this paper. The receiving coil of a wireless charger is usually designed to match with single transmitting coil and to have a fixed power level output.
2017-03-28
Technical Paper
2017-01-1247
Mohammed Khorshed Alam, Lihua Chen, Yan Zhou, Fan Xu, Shuitao Yang
Abstract Direct bypass to DC-DC boost converter in traction inverter increases converter's capability and efficiency significantly by providing a lower loss path for power flow between the battery and DC-link terminal. A bypass using diode is an excellent solution to achieve this capability at low cost and system complexity. Bypass diode operates in the linear operating region (DC Q-point) when the battery discharges through the bypass diode to drive the electric motors. Therefore, thermal stress on the DC-link capacitor is shared between the input and DC-link capacitors through the bypass diode. On the other hand, inverters introduce voltage oscillation in the DC-link terminal which results in unwanted energy oscillation through the bypass diode during battery charging. Both of these phenomena have been explained in details.
2017-03-28
Technical Paper
2017-01-1251
Bin Zhou, Jeffrey Burl, Amir Rezaei
Abstract This paper presents results on how the Equivalent Consumption Minimization Strategy (ECMS) penalty factor effects Lithium ion battery aging. The vehicle studied is the Honda Civic Hybrid. The battery used is A123 Systems’. Vehicle simulation using multiple combinations of highway and city drive cycles. For each combination of drive cycles, six ECMS penalty factor values are used. Battery aging is evaluated using a semi-empirical model combined with accumulated Ah-throughput method which uses, as an input, the battery state of charge trajectory from the vehicle simulations. The tradeoff between fuel cost and battery aging cost is explicitly displayed. In addition, the results provide insight into how driving behavior affects battery aging. The paper concludes with a discussion of the optimal balance between fuel cost and battery aging.
2017-03-28
Technical Paper
2017-01-1252
Ming Cheng, Lei Feng, Bo Chen
Abstract This paper studies the nonlinear model predictive control for a power-split Hybrid Electric Vehicle (HEV) power management system to improve the fuel economy. In this paper, a physics-based battery model is built and integrated with a base HEV model from Autonomie®, a powertrain and vehicle model architecture and development software from Argonne National Laboratory. The original equivalent circuit battery model from the software has been replaced by a single particle electrochemical lithium ion battery model. A predictive model that predicts the driver’s power request, the battery state of charge (SOC) and the engine fuel consumption is studied and used for the nonlinear model predictive controller (NMPC). A dedicated NMPC algorithm and its solver are developed and validated with the integrated HEV model. The performance of the NMPC algorithm is compared with that of a rule-based controller.
2017-03-28
Technical Paper
2017-01-1250
Tomokazu Ishikawa, Kouhei Ikebuchi, Kenji Nakamura, Osamu Ichinokura, Naoki Kurimoto, Yoshiaki Nishijima
Abstract An electromagnetic and motion-coupled analysis is made for a Switched Reluctance Motor (SRM) based on a Reluctance Network Analysis (RNA). A full-pitch-winding SRM is promising since it has a high torque density. Since the motor characteristics such as driving torque significantly depend on commutation pattern, an analysis coupled with motor motion and its drive circuit is requisite for the performance prediction. However, in the full-pitch-winding SRM, the relationship between the coil magnetomotive force and the core flux is complicated, and thus Finite Element Method (FEM) has been major method to predict the motor characteristics, which takes too much computational time for cycle calculations. An RNA treats the relationship of coil magnetomotive force and core flux as lumped parameter circuit, and thus enables fast computation with a macroscopic view of magnetic phenomena.
2017-03-28
Technical Paper
2017-01-1256
Mayank Garg, Christopher Rahn
Abstract Lithium ion (Li-ion) battery capacity selection for hybrid electric vehicles (HEVs) is primarily based on charge/discharge power and life. At high temperatures, battery degradation increases and reduces battery life, but battery internal resistance reduces and improves battery performance. Lithium ion phosphate (LFP) batteries have a maximum allowable voltage limit based on degradation minimization, so the battery capacity is selected large enough to stay within the limit over the entire life of the pack. This paper develops an optimal temperature trajectory for LFP cells to improve their charge acceptance and reduce HEV pack size while maintaining battery life. The proposed algorithm has two strategies. First, the battery pack temperature is increased when its state of charge (SOC) is high because the cell is more likely to exceed maximum voltage limit at high SOC.
2017-03-28
Technical Paper
2017-01-1254
Raja Sangili Vadamalu, Christian Beidl
Powertrain systems exploiting information from vehicle connectivity have widened the system boundary resulting in additional degrees-of-freedom for predictive trajectory planning. Heuristic methods based on component characteristics are currently widely used for Energy Management (EM) functionality of hybridized powertrains. Despite their better usability, increased calibration effort and sensitivity to synthetic calibration scenarios are drawbacks of such control methods. Availability of predictive data, better computing power and challenges posed by various scenarios in real driving, have led to interest in online-optimizing EM functionality. Equivalent Consumption Minimization Strategy (ECMS) approaches based on Indirect optimal control /Pontryagin Minimum principle have difficulty in handling inequality state constraints. Extensions of ECMS make use of modifications to the equivalence factor/co-state, based on prediction of driving conditions.
2017-03-28
Technical Paper
2017-01-1253
Somnath Sengupta, Chethan Gururaja, Sushant Hingane, Prajwal A K, Malay Maniar, Ondřej Mikuláš, Jaroslav Pekar
Abstract Increasingly strict CO2 and emissions norms are pushing the automotive industry towards increasing adoption of Hybrid Electric Vehicle (HEV) technology. HEVs are complex hardware systems which are often controlled by software that is complex to maintain, time-consuming to calibrate, and not always guaranteed to deliver optimal fuel economy. Hence, coordinated, systematic control of different subsystems of HEV is an attractive proposition. In this paper, Model Predictive Control (MPC) and Equivalent Consumption Minimization Strategy (ECMS) based supervisory controllers have been developed to coordinate the power split between the two prime movers of an HEV – internal combustion engine and electric motor. A dynamical physics based HEV model has been developed for simulation of the system behavior. A cost function has been formulated to improve fuel economy and battery life.
2017-03-28
Technical Paper
2017-01-1257
Haotian Wu
Abstract Previous studies have investigated various hybrid and electric powertrain architectures to balance concerns about the energy consumption and drivability. However, present architectures have some intrinsic drawbacks on the powertrain torque winding up, weight, packaging and energy harvest. This study proposed an electric powertrain that is powered by four independent motor drive. In order to investigate the drivability and regeneration braking performance, physics-based models of vehicle, motor and battery were developed; meanwhile, the dual-loop feedforward motor control and hybrid sliding mode control were presented. The Physics model-based evaluation was conducted by using the co-simulation technology of LMS AMESim and Simulink. The results show that the proposed four-wheel independent electric powertrain can achieve better drivability and regeneration braking performance. The proposed hybrid sliding mode control can converge faster than the bang-bang control.
2017-03-28
Technical Paper
2017-01-1288
Noriko Shisa, Shinsuke Ishihara, Yougui Huang, Mikio Asai, Katsuhiko Ariga
Abstract Despite the fact that methanol is toxic to human health and causes serious damage to automobile engines and fuel system components, methanol-containing gasoline is becoming popular in some areas. Methanol demonstrates similar chemical properties to ethanol (which is already established as an additive to gasoline), so that it is difficult to identify methanol-containing gasoline without performing proper chemical analysis. In this study, we report a low-cost, portable, and easy-to-operate sensor that selectively changes color in response to methanol contained in gasoline. The colorimetric sensor will be useful for automobile users to avoid methanol-containing gasoline upon refueling.
2017-03-28
Technical Paper
2017-01-0536
William Goodwin, Claudio Mancuso, Nicolas Brown
This paper describes how distributive computing along with statistical subsystem simulation can be applied to produce near production ready embedded vehicle software and calibrations. Coupling distributive computing and statistical simulation was first employed over a decade ago at General Motors to design and analyze propulsion subsystem hardware. Recently this method of simulation has been enhanced extending its capabilities to both test embedded vehicle code as well as develop calibrations. A primary advantage of this simulation technique is its ability to generate data from a statistically significant population of subsystems. The result is the acquisition of an optimal data set enabling the development of a robust design now including both embedded code and calibrations. Additionally it has been shown that there are significant economic advantages in terms of time and cost associated with this type of development when compared to traditional method.
2017-03-28
Technical Paper
2017-01-0537
Murat Ates, Ronald D. Matthews, Matthew J. Hall
Abstract A quasi-dimensional model for a direct injection diesel engine was developed based on experiments at Sandia National Laboratory. The Sandia researchers obtained images describing diesel spray evolution, spray mixing, premixed combustion, mixing controlled combustion, soot formation, and NOx formation. Dec [1] combined all of the available images to develop a conceptual diesel combustion model to describe diesel combustion from the start of injection up to the quasi-steady form of the jet. The end of injection behavior was left undescribed in this conceptual model because no clear image was available due to the chaotic behavior of diesel combustion. A conceptual end-of-injection diesel combustion behavior model was developed to capture diesel combustion throughout its life span. The compression, expansion, and gas exchange stages are modeled via zero-dimensional single zone calculations.
2017-03-28
Technical Paper
2017-01-0527
Arya Yazdani, Jeffrey Naber, Mahdi Shahbakhti, Paul Dice, Chris Glugla, Stephen Cooper, Douglas McEwan, Garlan Huberts
An accurate estimation of cycle-by-cycle in-cylinder mass and the composition of the cylinder charge is required for spark-ignition engine transient control strategies to obtain required torque, Air-Fuel-Ratio (AFR) and meet engine pollution regulations. Mass Air Flow (MAF) and Manifold Absolute Pressure (MAP) sensors have been utilized in different control strategies to achieve these targets; however, these sensors have response delay in transients. As an alternative to air flow metering, in-cylinder pressure sensors can be utilized to directly measure cylinder pressure, based on which, the amount of air charge can be estimated without the requirement to model the dynamics of the manifold.
2017-03-28
Technical Paper
2017-01-0624
Jiaxin Liu, Sicheng Qin, Yankun Jiang, Shumo He
Abstract In this work, a XD132 Road Roller from XCMG in China was employed as a research basis to study the heat exchange performance of the heat dissipation module under varied working conditions. The module in the XD132 consists of a cooling fan and three radiators. At first, the numerical investigation on the elementary units of radiators was performed to obtain Colburn j factor and Fanning friction f factor, which were used for the ε-NTU method to predict the radiator performance. The fan was numerically tested in a wind test tunnel to acquire the performance curve. The performance data from both investigations were transformed into the boundary conditions of the numerical vehicle model in a virtual tunnel. A field experiment was carried out to validate the simulation accuracy, and an entrance coefficient was proposed to discuss the performance regularity under four working conditions.
2017-03-28
Technical Paper
2017-01-0629
John Kuo, George Garfinkel
Abstract Thermal modeling of liquid-cooled vehicle traction battery assemblies using Computational Fluid Dynamics (CFD) usually involves large models to accurately resolve small cooling channel details, and intensive computation to simulate drive-cycle transient solutions. This paper proposes a segregated method to divide the system into three parts: the cells, the cold plate and the interface between them. Each of the three parts can be separated and thermally characterized and then combined to predict the overall system thermal behavior for both steady-state and transient operating conditions. The method largely simplifies battery thermal analysis to overcome the limitations of using large 3D CFD models especially for pack level dynamic drive cycle simulations.
2017-03-28
Technical Paper
2017-01-0627
Bo Yang, Peter Woyciesjes, Aleksei Gershun
Abstract In this paper, new test results in the use of electrochemical techniques to measure corrosion in extended life engine coolants are presented. Corrosion protection performance of the engine coolants (including both fresh coolants and simulated used coolants) for typical cooling system metals under heat rejecting and heat accepting surface corrosion conditions for both general corrosion and localized corrosion are measured under conditions similar to the ones encountered in vehicle engine cooling systems as a function of immersion time. Fleet tests of the coolants were also conducted. They are used to provide support on the electrochemical test methodologies adopted. The effective use of electrochemical techniques to aid the development of the next generation of extended life coolant technologies with improved corrosion protection performance and a longer service life will be demonstrated and discussed.
2017-03-28
Technical Paper
2017-01-0626
LeeAnn Wang, George Garfinkel, Ahteram Khan, Mayur Harsha, Prashanth Rao
Abstract When a driver completes an aggressive drive cycle on a hybrid vehicle, the High Voltage (HV) battery system may be at risk of exceeding the power limit temperature, due to continuous absorption of radiative and convective heat from the environment, such as from exhaust and pavement, even after key-off. In such a case, in the absence of active cooling, the vehicle may not be keyed-on until battery temperatures are reduced below critical values. A transient thermal analysis is conducted on a HV battery system to simulate the key-off operation using an effective Computational Fluid Dynamics (CFD) methodology. Two stages are considered in this methodology to capture the complexity of the geometry and the multiple phenomena that need to be simulated in the model. The introduced modeling technique can be used for Full Hybrid Electric Vehicle (FHEV) and Plug-in Hybrid Electric Vehicle (PHEV) transient key-off situations.
2017-03-28
Technical Paper
2017-01-0620
Chandrakant Parmar, Sethuramalingam Tyagarajan, Sashikant Tiwari, Ravindra Thonge, S Arun Paul
Abstract The engine compartment of passenger car application contains various source which radiates the produced heat and raises the temperature level of the compartment. The rise in compartment temperature increases the body temperature of individual component. The rise in body temperature of critical components can endanger the durability or functionality of the specific component or a system in which it operates. The aim of this paper is to strategize thermal protection of the rear mounted engine and its components of a vehicle having radiator and cooling fan mounted in front. An additional ventilation fan with speed sensor is fitted alongside rear mounted engine and a unique monitoring technique framed in the EMS ECU to protect critical components like HT cables, alternators, ECUs, wiring harness etc. from thermal damage. The EMS continuously monitors the engine speed, vehicle speed and the PWM signal of ventilation fan to ensure the intended operation of the ventilation fan.
2017-03-28
Technical Paper
2017-01-0631
David C. Ogbuaku, Timothy Potter, James M. Boileau
Abstract The need to increase the fuel-efficiency of modern vehicles while lowering the emission footprint is a continuous driver in automotive design. This has given rise to the use of engines with smaller displacements and higher power outputs. Compared to past engine designs, this combination generates greater amounts of excess heat which must be removed to ensure the durability of the engine. This has resulted in an increase in the number and size of the heat exchangers required to adequately cool the engine. Further, the use of smaller, more aerodynamic front-end designs has reduced the area available in the engine compartment to mount the heat exchangers. This is an issue, since the reduced engine compartment space is increasingly incapable of supporting an enlarged rectangular radiator system.
Viewing 241 to 270 of 16536