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2017-04-11
Journal Article
2017-01-9625
Souhir Tounsi
Abstract In this paper, we present a design and control methodology of an innovated structure of switching synchronous motor. This control strategy is based on the pulse width modulation technique imposing currents sum of a continuous value and a value having a shape varying in phase opposition with respect to the variation of the inductances. This control technology can greatly reduce vibration of the entire system due to the strong fluctuation of the torque developed by the engine, generally characterizing switching synchronous motors. A systemic design and modelling program is developed. This program is validated following the implementation and the simulation of the control model in the simulation environment Matlab-Simulink. Simulation results are with good scientific level and encourage subsequently the industrialization of the global system.
2017-03-28
Technical Paper
2017-01-0629
John Kuo, George Garfinkel
Detailed thermal modeling of liquid-cooled vehicle traction battery assemblies using Computational Fluid Dynamics (CFD) analysis techniques usually involves large models to accurately resolve small cooling channel details. For large battery packs, some of these meshes may exceed current computational capabilities or result in long and expensive computational efforts. Moreover, only steady-state thermal predictions are usually performed, as drive-cycle transient simulations become impractical due to the exceedingly long solving times. To tackle this problem, an innovative segregated method has been developed for thermal analysis of liquid-cooled traction batteries, where battery cells and their active cooling system are divided into three parts: the cell, the cold plate and the interface between them.
2017-03-28
Technical Paper
2017-01-0626
LeeAnn Wang, George Garfinkel, Ahteram Khan, Mayur Harsha, Prashanth Rao
When a driver completes an aggressive drive cycle on a hybrid vehicle, the High Voltage (HV) battery system may risk exceeding the power limit temperature, due to continuous absorption of radiative and convective heat from the exhaust and pavement, even after key-off. In such case, the vehicle may not be keyed-on after a certain time. A transient thermal analysis is conducted on a HV battery system to simulate the key-off operation using Computational Fluid Dynamics (CFD). The analysis is partitioned into two stages, due to complex geometry and multiple phenomena captured in the model. The first stage involves two steady-state simulations. The first simulation is to model the HV battery system, during an aggressive drive cycle. The second simulation is to model the vehicle at an idle condition immediately after the aggressive drive cycle.
2017-03-28
Technical Paper
2017-01-1645
Marjorie Myers
Harness and terminal manufacturers are working to support the Automotive industry’s need to reduce energy consumption (and costs) via weight savings initiatives by converting from Cu to Al electrical cables within the traditional open style cable harness termination manufacturing environment. As the Automotive industry is fully aware, terminating nominally same sized Al cable to existing Cu cable designed terminals is neither a functional, nor a reliable, equivalent option – termination design changes are required to be able successfully qualify any such Al cable to Cu terminal connections for Automotive applications. In addition, the harness industry are looking for any new Al ‘open’ crimp termination designs to work well within the existing manufacturing and connector/harness design environment; e.g., ‘open’ crimp termination, on par termination process speed, no post-treatment, etc.
2017-03-28
Technical Paper
2017-01-0797
Sahil Sane, Tamer Badawy, Naeim Henein
Cold starting problems of diesel engines are caused mainly by the failure of the auto-ignition process or th¬e subsequent combustion of the rest of the charge. The problems include long cranking periods and combustion instability leading to an increase in fuel consumption in addition to the emission of undesirable unburned hydrocarbons which appear in the exhaust as white smoke. The major cause of these problems is the low temperature and pressure of the charge near the end of the compression stroke and/or the poor ignition quality of the fuel. This paper presents the results of an experimental investigation on the cold start of a high speed on ULSD and JP8 fuels. A detailed analysis is made of the autoignition and combustion of the two fuels in the first few cycles in the cold start transient. In addition, a comparison is made between these processes for the two fuels during idle operation.
2017-03-28
Technical Paper
2017-01-1256
Mayank Garg, Christopher Rahn
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
2017-01-1224
Ryota Kitamoto, Shinnosuke Sato, Hiromichi Nakamura, Atsushi Amano
A new fuel cell voltage control unit (FCVCU) was developed for a new fuel cell vehicle (FCV). In order to simultaneously reduce the electric powertrain size and increase the driving motor power, an FCVCU is needed to boost the voltage supplied from the fuel cell stack (FCSTK) 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 and loss of 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 to approximately 30% compared to the conventional VCU inductor. The heat generated by the smoothing capacitor increases together with the current.
2017-03-28
Technical Paper
2017-01-1667
Scott Piper, Mark Steffka, Vipul Patel
With the increasing content of electronics in automobiles and faster development times, it is essential that electronics hardware design and vehicle electrical architecture is done early and correctly. Today, the first designs are done in the electronic format with circuit and CAD design tools. Once the initial design is completed, several iterations are typically conducted in a “peer review” methodology to incorporate “best practices” before actual hardware is built. Among the many challenges facing electronics design and integration is electromagnetic compatibility (EMC). Success in EMC starts at the design phase with a relevant “lessons learned” data set that encompasses component technology content, schematic and printed circuit board (PCB) layout, and wiring using computer aided engineering (CAE) tools.
2017-03-28
Technical Paper
2017-01-1217
Jiangong Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai
An alternating current (AC) heating method for a NMC lithium-ion battery with 8Ah capacity is proposed in the paper. 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. 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 obtains the maximum temperature rise at 64A and 1Hz, which takes 1800s to heat up the battery from -25oC to 18oC.
2017-03-28
Technical Paper
2017-01-1681
Kyaw Soe
This paper describes a test system for improving the completeness, representativeness (hence usage and effectiveness) of automotive E/E test benches (enables more testing). A proportion of testing for automotive electrical and electronics systems and components is conducted using E/E testing boards (“testboards”). These are table like rigs consisting of most or all electrical and electronic parts connected together as per a car/truck/van. A major problem is that the testing is conducted on the equivalent of a static vehicle: testboards lack basic dynamic elements such as a running engine, vehicle motion, environmental, component and fluid temperatures, etc. This limits the testing that can be carried out on such a testboard. One solution is to provide one (or more) facilities to simulate and stimulate the electrical/electronic signals needed to effectively replace these missing dynamic elements (such as engine speed, vehicle speed and power supply voltage fluctuations).
2017-03-28
Technical Paper
2017-01-1227
Ali Najmabadi, Michael Kress, Brett Dryer, Ahmad Arshan Khan
This paper studies different switching schemes for loss reduction in a traction motor drive. The system under examination is composed of a battery, a 2 level Voltage Source Inverter, and an Interior Permanent Magnet motor. Discontinuous PWM (DPWM) control strategy is widely used in this type of motor drive for the reduction of losses. In some publications, the effect of the DPWM modulation scheme is compared to the reduction of the switching frequency which can also cause a reduction in switching losses of the inverter. Extensive studies have examined the effect of variation of the switching frequency on the motor and inverter losses. However, the effect of applying both switching schemes simultaneously has not been explored. This paper will use a system that is operated at a fixed switching frequency as the baseline. Afterwards, three different switching schemes will be studied and compared to the baseline.
2017-03-28
Technical Paper
2017-01-1247
Mohammed Khorshed Alam, Lihua Chen, Yan Zhou, Fan Xu, Shuitao Yang
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. The 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. Inverters introduce voltage oscillation in the DC-link terminal during battery charging through regenerative operation and results in unwanted power oscillation through the bypass diode. Both of these phenomena have been investigated in details.
2017-03-28
Technical Paper
2017-01-1190
Patrick Maguire, Hyung Baek, Stephen Liptak, Olivia Lomax, Rodolfo Palma, Yi Zhang
As electrified powertrains proliferate through original equipment manufacturer vehicle offerings, the focus on system cost and weight reduction intensifies. This paper describes the development and evaluation of a high voltage (HV) battery system enclosure molded from high density polyethylene (HDPE) to deliver substantial cost and weight opportunities. While previous battery enclosure alternatives to steel and aluminum have focused on thermoset composites and glass filled polypropylene, this solution leverages HDPE design techniques established for fuel tanks and applies them to a HV battery, with some notable differences such as employing two injection molded halves which are joined via infrared welding. The result is a tough, energy absorbing structure, capable of hermetic sealing, which simplifies manufacturing by eliminating nearly all fasteners.
2017-03-28
Technical Paper
2017-01-1204
Xiao Yang, Ted Miller
We try to understand the fast recharge capability of Li-ion batteries and its effect on capacity degradation. We find out that 5 Ah prismatic Li-ion cells can be fully recharged in 3 minutes under a constant rate of 20C, or in 2 min (25.5C) from 0% to 85% SOC (state of charge) without undue stresses. We cycle the battery at 16C charge rate from 0 to 100%SOC and do not see any unexpected battery capacity loss in 50 cycles, where half of the cycles are 1C-rate charge as a reference capacity check. We realize that the batteries under the fast charge study do not experience mass transport limitations in either solid electrodes or the electrolyte system.
2017-03-28
Technical Paper
2017-01-0398
Robert A. Smith, Allison Ward, Daniel Brintnall
Utilization of TGA Flynn-Wall and Arrhenius Analysis for Rapid Prediction of Automotive PVC Cable Performance Robert Alan Smith, Allison Ward, and Daniel D. Brintnall Delphi Electrical/Electronic Architecture 4551 Research Parkway Warren, Ohio 44483 Poly(vinylchloride), PVC, insulated cable was first used in automobiles in the 1940’s when the average vehicle contained 40 meters of wiring. Presently, the Bentley Bentayga has a wiring harness that weighs 110 lbs! Indeed, the electrical systems of automobiles have become much more complicated than just provision of lighting, signaling, and heat with the evolution of climate control, infotainment and data delivery systems. Due to low cost and light weight, PVC insulated cable is still the most widely used cable in automobiles and is found predominantly in non-engine compartment applications limited by an upper use temperature of 80◦ C.
2017-03-28
Technical Paper
2017-01-1219
Steven G. Rinaldo, Zhihong Jin, Perry Wyatt
Validating the state-of-function (SOF) algorithm is critical for battery management as it is responsible for battery power utilization as well as safety protection and life. The SOF accomplishes this optimization task by communicating battery level operational limits related to power, current, voltage and temperature. Ultimately these operational limits are predicted via parameters derived from component models. Correspondingly, any errors within the component models will propagate into the reported SOF limits. Developing an efficient SOF validation methodology will facilitate the understanding of SOF performance gaps. In this work, we developed a methodology that consists of simulating the cell model response and SOF output for a set of current pulse events that span operational boundaries defined by temperature, initial state-of-charge, pulse time and current magnitude.
2017-03-28
Technical Paper
2017-01-0190
Neelakandan Kandasamy, Steve Whelan
The range of Plug-In Electric Vehicles is highly influenced by the electric power consumed by various sub systems, the major part of the power being used for vehicle climate control strategies in order to ensure an acceptable level of thermal comfort for the passengers. Driving range decreases with low temperatures in particular because cabin heating system requires an important amount of electric power. Range also decreases with high ambient temperatures because of the air conditioning system with electrically-driven compressor its affect the EV driving range, the reduced EV driving range under real life operating cycles, which can be a barrier against market penetration. The structure of a vehicle is capable of absorbing a significant amount of heat when exposed to hot climate conditions. 50-70% of this heat penetrates through the glazing and raises both the internal cabin air temperature and the interior trim surface temperature.
2017-03-28
Technical Paper
2017-01-1686
Muhammad Askar
A vehicle's electrical system is one of the top sources of problems requiring service. Electronic means of service documentation have been replacing static documents as a way of speeding vehicle troubleshooting. The next step on this path of evolution is to turn those into smart maintenance systems, capable of offering technicians true data insights, and highly-efficient diagnostic procedures. This paper briefly summarizes the technologies underpinning the evolution in electrical system diagnosis and repair; which include schematic layout automation using prototypes and rule-based styling, instant language translation, 2D/3D view links with schematics, interactive diagnostic procedures, and dynamically-generated signal-tracing diagrams. These technologies empower after sales service teams with state-of-the-art capabilities; which not only reduce costs but also improve the quality of the brand in the eyes of its customers.
2017-03-28
Technical Paper
2017-01-1734
Bo-Chiuan Chen, Guo-Shun Chuang
Lithium-ion batteries (LIB) have been widely used in modern electric vehicles. The reliable, efficient, and safe operation of LIB requires monitoring, control and management. An accurate estimation of the state of charge (SOC) is necessary not only for optimal energy management but also for protecting the LIB from being deeply discharged or overcharged. In this paper, an equivalent circuit model (ECM) is used to simulate the dynamic behavior of LIB. Parameters of internal resistance, diffusion resistance and diffusion capacitance are identified using the recursive least square method. Because open circuit voltage (OCV) and SOC have an obviously nonlinear relationship, an extended Kalman filter (EKF) is used to estimate the SOC based on the ECMS model. Despite the nonlinearity of the SOC-OCV curve, the SOC has small variations for ordinary charging or discharging current rates. The curve can be approximated by a straight line with the slope and intersection changing at different SOCs.
2017-03-28
Technical Paper
2017-01-0631
David C. Ogbuaku, Timothy Potter, James M. Boileau
The competing demands for weight reduction and high performance in modern automobiles mean that manufacturers must use engines with smaller displacements and higher power outputs. Compared to past engine designs, this combination inherently generates more heat that must be removed to ensure the durability of the engine. This situation has led to the need for radiator and other heat-exchanger systems that can reduce weight while maintaining the engine at acceptable operating temperature limits. Further, the desire for more fuel efficient vehicles and lower emissions footprints has led to smaller, more aerodynamic frontend designs in modern automobiles. Therefore, the area available in the engine compartment to mount the heat exchangers has become smaller while the number and size of the heat exchangers required to adequately cool the engine have increased.
2017-03-28
Technical Paper
2017-01-1198
Po Hong, Hongliang Jiang, Jian qiu Li, Liangfei Xu, Minggao Ouyang
The lithium-ion battery plays an important role in saving energy and lowering emissions. Many parameters like temperature have influence on the characteristic of the battery and in an electric vehicle this phenomenon becomes more serious. Estimating these parameters is kind of challenging work and many available approaches have been studied such as Kalman filter and offline AC impedance. In this paper, the application of a boost DC/DC converter to the battery system of high power for online AC impedance identification is proposed. The function of the converter is to inject a current fluctuation signal into the battery at work and the normal output current is drawn by a load. Through analyzing the average state space equations and deriving the small signal model of the converter, the gain function is deduced of the fluctuated current signal against the fluctuated duty cycle which controls the converter.
2017-03-28
Technical Paper
2017-01-1236
Shuitao Yang, Lihua Chen, Mohammed Khorshed Alam, Fan Xu, Yan Zhou
Boost converter is used to boost the high voltage (HV) battery voltage to a higher dc-link voltage in some HEV traction inverter applications. The main advantages for the system with Boost converter are: 1) using the boost converter, traction inverter is de-coupled from battery voltage fluctuations causing it to be over-sized, 2) with higher dc-link voltage, traction inverter could achieve higher torque capability for motor especially at high speed condition. When designing this Boost converter, the switching frequency is a key parameter for the converter design. Switching frequency is directly related to the power loss (specifically switching loss) of IGBTs of a Boost converter. Moreover, it will also change the converter operation, causing different inductor ripple current, input battery ripple current as well as input capacitor ripple current. Therefore, the selection of switching frequency is very important to the performance of both active and passive components.
2017-03-28
Technical Paper
2017-01-1228
Masaya Nakanishi
Motor vehicle industry is expected to reduce CO2 emission more and more for protecting the environment. Alternator, which supplies electric energy to battery and electrical loads when it is rotated by engine via belt, is one of key components to improve vehicle fuel efficiency. That’s because actual one is greatly affected by electrical loads, and improving alternator efficiecy is effective to enhance actual one. We have reduced rectification loss from AC to DC with MOSFET instead of rectifier diode because on voltage of MOSFET is much lower than diode drop, which results in improving alternator efficiency. Control circuit is required to drive MOSFET because it is an active element. It is important to turn MOSFET ON and OFF during rectification period “synchronous control”. It is turned ON while a rectifier current flows through MOSFET as alternator output, and turned OFF while the current doesn’t flow to avoid drawing in a reverse current from battery.
2017-03-28
Technical Paper
2017-01-1240
Koki Matsushita
Demands for improving fuel economy and reducing carbon dioxide emmision in automobiles have been increasing rapidly. Since the ratio of alternator loss to entire loss of automobile is high, reducing the alternator loss is effective for fuel economy improvement. The alternator loss consists of three main losses; copper loss, iron loss and rectification loss. Above all, the ratio of rectification loss to the alternator loss, which is approximately 30%, is relatively high. DENSO has developed “MOS rectifier” to reduce the rectification loss. The MOS rectifier is a commutating device which has MOSFETs as rectifying devices instead of diodes. The MOS rectifier contributes to fuel economy improvement of automobiles by reducing rectification loss with low On-Resistance(Ron) MOSFET. Since the MOS rectifier is exposed to severe temperature environment from -40 °C to 120 °C, temperature stress on solder and Aluminium wire is large.
2017-03-28
Technical Paper
2017-01-0624
Jiaxin Liu, Sicheng Qin, Yankun Jiang, Shumo He
In this work, a XD132 Road Roller from XCMG in China was employed as the research basis to study the heat exchange performance for the heat dissipation module under varied working conditions. The module in XD132 consists of a cooling fan and a radiator group. At first, a numerical investigation on the elementary unit of the radiator was performed to obtain Colburn j factor and Fanning f factor, which was used for the -NTU method that predicts the radiator performance. The fan was numerically tested in a virtual tunnel to acquire the performance curve. The performance data from both investigations were transformed into the boundary conditions for the numerical model in a virtual tunnel. A field experiment was carried out to validate the simulation accuracy, and the performance regularity under four working conditions were discussed.
2017-03-28
Technical Paper
2017-01-0620
Chandrakant Parmar, Sethuramalingam Tyagarajan, Sashikant Tiwari, Ravindra Thonge, S Arun Paul
The engine compartment of passenger car application contain various source which radiates the produced heat and raises the temperature level of the compartment. The rise in compartment temperature increases the individual component body temperature. The rise in body temperature of critical components can endanger the life or functionality of the specific component or a system in which it operates. The aim of this paper is to strategise thermal protection of the rear mounted engine and it's 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, ECU, 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
2017-01-0627
Bo Yang, Peter Woyciesjes, Aleksei Gershun
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 surface 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 test of the coolants were also conducted. They are used to provide technical 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
2017-01-0275
N. Obuli Karthikeyan, N. Prajitha, P. Sethu Madhavan
As the technology gets upgraded every day, automotive manufacturers are also paying more attention towards delivering a highly reliable product which performs its intended function throughout its useful life without any failure. To develop a reliable product, functional and durability testing is not only sufficient rather it should undergo various types of stresses at different levels, to identify its potential modes of failure. By reliability testing, most of the failure modes of a component can be analyzed and eliminated in the design stage itself, prior to production. In this paper, electrical relay of a commercial vehicle was taken up for study to analyze the causes for field failure and to estimate its reliable life in the customer operating conditions. Few of the field failure samples were tested for its performance characteristics with typical testing protocol and strip out experiment was carried out to analyze the various failure modes.
2017-03-28
Technical Paper
2017-01-0137
Akira Ando, Koichi Hamashima, Shinji Kato, Noriyuki Tomita, Takahiro Uejima
In respect to the present large refrigerator trucks, a sub-engine type is main product, but the basic structure does not greatly change since the introduction for around 50 years. A sub-engine driving a compressor uses an engine for the industrial instrument, and the environmental correspondence such as the fuel consumption, the emission is late remarkably. In addition, most of trucks carry the truck equipment including the refrigerator which consumes the fuel about 20% of whole vehicle. Focusing on this point, the follows are the report about the manufacture of the system planning the fuel consumption reduction of the large size refrigerator truck by a new concept to use HV power supply for the electric-driven refrigerator. We have developed a fully electric-driven refrigerator system, which uses regenerated energy that is, dedicated for the refrigerator system.
2017-03-28
Technical Paper
2017-01-0893
Marek Tatur, Kiran Govindswamy, Dean Tomazic
Abstract Demanding CO2 and fuel economy regulations are continuing to pressure the automotive industry into considering innovative powertrain and vehicle-level solutions. Powertrain engineers continue to minimize engine internal friction and transmission parasitic losses with the aim of reducing overall vehicle fuel consumption. Strip friction methods are used to determine and isolate components in engines and transmissions with the highest contribution to friction losses. However, there is relatively little focus on friction optimization of Front-End-Accessory-Drive (FEAD) components such as alternators and Air Conditioning (AC) compressors. This paper expands on the work performed by other researchers’ specifically targeting in-depth understanding of system design and operating strategy.
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