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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
2017-01-1645
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
2017-01-0893
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.
2017-03-28
Technical Paper
2017-01-1180
Stefan Brandstätter, Michael Striednig, David Aldrian, Alexander Trattner, Manfred Klell, Tomas Dehne, Christoph Kügele, Michael Paulweber
Abstract The limitation of global warming to less than 2 °C till the end of the century is regarded as the main challenge of our time. In order to meet COP21 objectives, a clear transition from carbon-based energy sources towards renewable and carbon-free energy carriers is mandatory. Polymer electrolyte membrane fuel cells (PEMFC) allow an energy-efficient, resource-efficient and emission-free conversion of regenerative produced hydrogen. For these reasons fuel cell technologies emerge in stationary, mobile and logistic applications with acceptable cruising ranges as well as short refueling times. In order to perform applied research in the area of PEMFC systems, a highly integrated fuel cell analysis infrastructure for systems up to 150 kW electric power was developed and established within a cooperative research project by HyCentA Research GmbH and AVL List GmbH in Graz, Austria. A novel open testing facility with hardware in the loop (HiL) capability is presented.
2017-03-28
Technical Paper
2017-01-1187
Tatsuya Sugawara, Takuma Kanazawa, Naoki Imai, Yu Tachibana
Abstract This paper describes the motorized turbo compressor, which is a key technology for reducing the size of the fuel cell system for the Clarity Fuel Cell. The oxygen needed for fuel cell power generation is sent into the fuel cell by compressing the air from the atmosphere by a compressor. The conventionally used Lysholm compressor needed numerous sound absorbers, such as silencers and covers, to help achieve quietness when driving. Therefore, changing to a turbo compressor enhanced quietness and helped to eliminate or reduce the size of these auxiliary sound absorbers. Furthermore, a two-stage supercharging structure was used and the air pressure supplied to the fuel cell was increased to 1.7 times the previous air pressure. This increased the fuel cell power, which enabled to reduce the number of cells needed, and reduced the needed humidification amount which enabled to reduce the size of the humidifier. These enhancements helped to reduce the system size.
2017-03-28
Technical Paper
2017-01-1189
Tsuyoshi Maruo, Masashi Toida, Tomohiro Ogawa, Yuji Ishikawa, Hiroyuki Imanishi, Nada Mitsuhiro, Yoshihiro Ikogi
Abstract Toyota Motor Corporation (TMC) has been developing fuel cell vehicles (FCVs) since 1992. As part of a demonstration program, TMC launched the FCHV-adv in 2008, which established major technical improvements in key performance areas such as efficiency, driving range, durability, and operation in sub-zero conditions. However, to encourage commercialization and widespread adoption of FCVs, further improvements in performance were required. During sub-zero operating conditions, the FC system output power was lower than under normal operating conditions. The FC stack in the FCHV-adv needed to dry the electrolyte membrane to remove unneeded water from the stack. This increased the stack resistance and caused low output power. In December 2014, TMC launched the world’s first commercially available FCV named the Mirai, which greatly improved output power even after start-up in sub-zero conditions.
2017-03-28
Technical Paper
2017-01-1188
Daisuke Hayashi, Atsushi Ida, Shota Magome, Takahisa Suzuki, Satoshi Yamaguchi, Ryosuke Hori
Abstract The key challenge in designing a high power density fuel cell is to reduce oxygen transport loss due to liquid water. However, liquid water transport from catalyst layers to channels under operating conditions is not completely understood. Toyota developed a high resolution space and time liquid water visualization technique using synchrotron x-ray (Spring-8) radiography. In addition, a simulation method was created based on computational fluid dynamics (CFD) to identify the cell performance relationship to water distribution. The relationship among gas diffusion layer (GDL) parameters, water distribution, and fuel cell performance was clarified by combining the techniques Toyota developed.
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
2017-01-1212
Hong Jia Hong, Jesus Ruiz Sevillano, Clemens Kain, Guenter Hofer, Karl Felber, Wai Keung Chan
Abstract The automotive industry is moving from fossil carburant to electric drive trains due to the stringent CO2 reduction policies. In this context, the electric energy storage becomes one of the key parameters of successful rolling out electrified vehicles. Typical battery management systems comprises of battery cells measurement and monitoring, balancing function, temperature monitoring, together with the State of Charge and State of Health estimations based on the given measurements. Together with the functions above, a robust internal IC communication protocol is one of the key parameters to guarantee battery performance as well as safety. This paper focuses on the automotive battery communication system. On one side, the importance of the communication system and its impact in the EDT (electric drive train) is discussed including safety aspects. Later on, the different communication methods up to date are analyzed to further understand their limitations.
2017-03-28
Technical Paper
2017-01-1186
Chunmei Wang, Shinichi Hirano
Abstract This study investigates a system and a method to enhance fuel cell vehicle robustness during vehicle start/stop cycle by mitigating cathode half-cell potential spikes. Multiple dynamic hydrogen reference electrodes were installed in the fuel cell under test to observe changes of anode and cathode half-cell potentials during simulated system startup and shutdown conditions. Multiple reference electrodes were used to measure localized anode and cathode half-cell potentials in an active area. A 1.4-1.8 V half-cell potential spike at the cathode in the startup condition was observed due to a hydrogen/air boundary formed within the anode flow field. Various system solutions have been studied to contain the cathode half-cell potential spikes, such as purging with inert gas, or inserting a shunt resistor as a shorting component between the anode and the cathode. In this study, a method of connecting an electrical load prior to flowing hydrogen fuel to the cell was tested.
2017-03-28
Technical Paper
2017-01-0013
Gaurav Gupta, Ujjwal Modi
Abstract Flickering problems in automotive vehicles have been observed from long time. After assessing numerous vehicles it was observed that whenever the hazard lights in a vehicle are activated, it leads to flickering problems in lights/small electrical components. This paper is to provide the solution for flickering snags in electrical components in a vehicle. The lights that are analyzed to be flickering/wavering are generally small loads such as LEDs in the bus roof area, small parking lamps, LEDs used in instrument clusters, cabin lamps, etc. The flickering in lights can turn out to be very unappealing at certain times. This absurd behavior can lead to extreme discomfort to the passengers and can also be a source of major distraction to the driver. This study presents the design & development for a vehicle platform & implementation that assesses the problem. Because of abrupt behavior of flasher circuits, voltage surges are observed, leading to flickering problems.
2017-03-28
Technical Paper
2017-01-1667
Scott Piper, Mark Steffka, Vipul Patel
Abstract 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
2017-01-1681
Kyaw Soe
Abstract This paper describes a test system for improving the completeness and representativeness of automotive electrical/electronic (E/E) test benches. This is with the aim to enable more testing and hence increase the usage and effectiveness of these facilities. A proportion of testing for automotive electrical and electronics systems and components is conducted using E/E testing boards (“test-boards”). 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: test-boards 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 test-board.
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
2017-01-1227
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
2017-01-0937
David Culbertson, James Pradun, Magdi Khair, Jeff Diestelmeier
Abstract Tightening regulations throughout the world demand a reduction in fuel consumption and NOX emission levels, creating an increasing need for additional heat for SCR aftertreatment. A durable and low cost heating system is needed for vehicles with hybrid or 24Vdc electricity. Recent development efforts have resulted in much smaller and lower cost heating systems for electrical systems ranging from 400 to 24Vdc. Test results demonstrate the feasibility of reducing the size of the heater and the relationship of heater power to the amount of time required to heat the exhaust. Intelligent solid state switching enables the heater to be smaller without compromising durability.
2017-03-28
Technical Paper
2017-01-1194
Qiaohua Fang, Xuezhe Wei, Haifeng Dai
Abstract Parallel-connected modules have been widely used in battery packs for electric vehicles nowadays. Unlike series-connected modules, the direct state inconsistency caused by parameter inconsistency in parallel modules is current and temperature non-uniformity, thus resulting in the inconsistency in the speed of aging among cells. Consequently, the evolution pattern of parameter inconsistency is different from that of series-connected modules. Since it’s practically impossible to monitor each cell’s current and temperature information in battery packs, considering cost and energy efficiency, it’s necessary to study how the parameter inconsistency evolves in parallel modules considering the initial parameter distribution, topology design and working condition. In this study, we assigned cells of 18650 format into several groups regarding the degree of capacity and resistance inconsistency. Then all groups are cycled under different environmental temperature and current profile.
2017-03-28
Technical Paper
2017-01-1195
Masahiro Kimoto
Abstract SAE standards require the function of a Manual Service Disconnect (MSD), when open, to remove any voltage between positive and negative Rechargeable Energy Storage System (RESS) output terminals. Another SAE standard specifies that measured voltage across all external battery terminal sets shall be less than 60 VDC within 5 seconds after the manual disconnect is actuated with the automatic disconnect (e.g., contactors) closed. In this paper, the location of the manual service disconnect is reviewed to meet isolation requirement of the battery pack system (i.e., RESS). Battery architectures with manual service disconnect located at the most positive side, most negative side, and center of the array or the pack were studied. Voltage measurement points and single point failure modes were considered. It was found that MSD location for a single contactor pack is most effective in reducing voltage potential at the terminals when placed on the other side of the contactor.
2017-03-28
Technical Paper
2017-01-1192
Amardeep Sidhu, Afshin Izadian, Sohel Anwar
In this paper, multiple-model adaptive estimation techniques have been successfully applied to fault detection and identification in lithium-ion batteries. The diagnostic performance of a battery depends greatly on the modeling technique used in representing the system and the associated faults under investigation. Here, both linear and non-linear battery modeling techniques are evaluated and the effects of battery model and noise estimation on the over-charge and over-discharge fault diagnosis performance are studied. Based on the experimental data obtained under the same fault scenarios for a single cell, the non-linear model based detection method is found to perform much better in accurately detecting the faults in real time when compared to those using linear model based method.
2017-03-28
Technical Paper
2017-01-1191
Patrick Wesskamp, Simon Reitemeyer, Joachim Melbert
Abstract This work provides a new method for estimating the capacity of an automotive Lithium-Ion cell under real application conditions present in Hybrid and Electrical vehicles. Reliable online capacity estimation is needed for accurate prediction of the remaining electrical driving range. This is a crucial criterion for customer acceptance of Electrical vehicles. Dynamic excitations of real driving cycles, temperature variation as well as the variation of electrical battery behavior with capacity and resistance degradation are challenges that need to be overcome. For this paper, a long-term aging study on 120 automotive Lithium-Ion cells is evaluated with respect to the correlation between electrical cell behavior, temperature and the cell capacity over the complete cell lifetime. The results are used for a dynamic state-space model which provides the current-voltage relationship valid for all aging states of the battery.
2017-03-28
Technical Paper
2017-01-1205
Letao Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai
Abstract To monitor and guarantee batteries of electric vehicles in normal operation, battery models should be established primarily for the further application in battery management system such as parameter identification and state estimation including state of charge (SOC), state of health (SOH) and so on. In this paper, an improved battery modeling method is proposed which is based on the recursive least square (RLS) algorithm employing an optimized objective function. The proposed modified objective function not only includes the normal sum of voltage error squares between measured voltage and model output voltage but also introduces a new variable representing the sum of first order difference error squares for both kinds of voltages. This specialty can undoubtedly guarantee better agreement for the measured output and the model output. The battery model used in this paper is selected to be the conventional second order equivalent circuit model.
2017-03-28
Technical Paper
2017-01-1203
Takashi Inamoto, Lawrence Alger
Abstract Recent electric vehicles use Li-ion batteries to power the main electric motor. To maintain the safety of the main electric motor battery using Li-ion cells, it is necessary to monitor the voltage of each cell. DENSO has developed a battery Electronic Control Unit (ECU) that contributes greatly to the reduction of the cost and the improvement of the reliability of the system. Each manufacturer has been developing a dedicated IC for monitoring the voltages of each cell of a battery. However, since the number of cells that can be monitored is limited, more than one IC is required to measure the voltages of a large number of cells. The increase in the number of ICs and the amount of insulator leads to the rise in system cost. DENSO has developed a dedicated IC that uses a proprietary high-breakdown voltage process, and which enables monitoring up to 24 cells with a single IC chip.
2017-03-28
Technical Paper
2017-01-1202
Ben Tabatowski-Bush
Abstract The Battery Monitoring Integrated Circuit (BMIC) is a key technology for Battery Electronics in the electrification of vehicles. Generally speaking, every production hybrid, plug-in hybrid, and battery electric vehicle uses some type of BMIC to monitor the voltage of each lithium battery cell. In order to achieve Functional Safety for the traction battery packs for these electrified vehicles, most designs require higher ASIL ratings for the BMIC such as C or D. For the entire market of available BMIC’s, there is a generic feature set that can be found on almost every IC on the market, such as a front end multiplexer, one or more precision references, one or more Analog to Digital (A/D) converters, a power supply, communications circuits, and window comparators. There is also a fairly consistent suite of self-diagnostics, available on just about every available BMIC, to detect failures and enable achievement of the appropriate ASIL rating.
2017-03-28
Technical Paper
2017-01-1200
Vijay Saharan, Kenji Nakai
Abstract Electric vehicles have a strong potential to reduce a continued dependence on fossil fuels and help the environment by reducing pollution. Despite the desirable advantage, the introduction of electrified vehicles into the market place continues to be a challenge due to cost, safety, and life of the batteries. General Motors continues to bring vehicles to market with varying level of hybrid functionality. Since the introduction of Li-ion batteries by Sony Corporation in 1991 for the consumer market, significant progress has been made over the past 25 years. Due to market pull for consumer electronic products, power and energy densities have significantly increased, while costs have dropped. As a result, Li-ion batteries have become the technology of choice for automotive applications considering space and mass is very critical for the vehicles.
2017-03-28
Technical Paper
2017-01-1199
Khalid Khan, Bin Zhou, Amir Rezaei
Abstract A high voltage battery is an essential part of hybrid electric vehicles (HEVs). It is imperative to precisely estimate the state of charge (SOC) and state of health (SOH) of battery in real time to maintain reliable vehicle operating conditions. This paper presents a method of estimating SOC and SOH through the incorporation of current integration, voltage translation, and Ah-throughput. SOC estimation utilizing current integration is inadequate due to the accumulation of errors over the period of usage. Thus voltage translation of SOC is applied to rectify current integration method which improves the accuracy of estimation. Voltage translation data is obtained by subjecting the battery to hybrid pulse power characterization (HPPC) test. The Battery State of Health was determined by semi-empirical model combined with accumulated Ah-throughput method. Battery state of charge was employed as an input to estimate damages accumulated to battery aging through a real-time model.
2017-03-28
Technical Paper
2017-01-1197
Aziz Abdellahi, Saeed Khaleghi Rahimian, Berislav Blizanac, Brian Sisk
Abstract 48V battery packs, with rated power capabilities on the order of 8-16kW, are rapidly becoming a new standard in the automotive industry. Improving on their 12V counterparts (2-5kW), 48V Mild Hybrid Electric Vehicles (MHEV) allow for extended start-stop and regenerative braking functionalities, providing fuel economy benefits of up to 10-15% in standard passenger vehicles. New and relatively unexplored opportunities exist to further increase the fuel economy and performance of 48V systems. Improvement in battery power (to ~25kW) would further enable hybridization to near-HEV levels as well as engine downsizing, thus paving the way to fuel economy improvements beyond the current 10-15% MHEV limit. Additionally, new electrified features may be added, such as electric turbo/supercharging, electric traction, electric power steering, electric suspension and electric air conditioning.
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
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
2017-01-1240
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
2017-01-1211
SoDuk Lee, Jeff Cherry, Michael Safoutin, Joseph McDonald
Abstract As part of the Midterm Evaluation of the 2017-2025 Light-duty Vehicle Greenhouse Gas Standards, the U.S. Environmental Protection Agency (EPA) developed simulation models for studying the effectiveness of stop-start technology for reducing CO2 emissions from light-duty vehicles. Stop-start technology is widespread in Europe due to high fuel prices and due to stringent EU CO2 emissions standards beginning in 2012. Stop-start has recently appeared as a standard equipment option on high-volume vehicles like the Chevrolet Malibu, Ford Fusion, Chrysler 200, Jeep Cherokee, and Ram 1500 truck. EPA has included stop-start technology in its assessment of CO2-reducing technologies available for compliance with the standards. Simulation and modeling of this technology requires a suitable model of the battery. The introduction of stop-start has stimulated development of 12-volt battery systems capable of providing the enhanced performance and cycle life durability that it requires.
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