Browse Topic: Electrical systems

Items (15,917)
The high-performance electric sports cars market is expected to register rapid development in the next years, driven by a different attitude of racing enthusiasts toward electric vehicles. The improvements in battery technology are reinforcing consumer confidence and interest in electric sports vehicles, making them more attractive to enthusiasts and accelerating their adoption. Batteries have been used in high heat generation conditions more often with fast charging and discharging. Therefore, the need for more advanced battery thermal management systems (BTMS) has been increasing in recent years. Vegetable oil, owing to its unique availability and biodegradability, is considered as a viable alternative to fossil fuel-based cooling fluids in immersion cooling systems. In the present work, the feasibility of using vegetable oil in immersion cooling under high discharge conditions is studied by comparing it with four types of fossil fuel-based cooling fluids. Immersion cooling was
Hong, HanchiSong, XiangShi, Xud’Apolito, LuigiXin, Qianfan
In this study, a strategy for MCCI combustion of a novel alcohol fuel is demonstrated. The novel fuel, “GrenOl”, is the result of the catalytic upgrade of sustainable ethanol into alcohols of higher molecular weight. The composition of GrenOl includes approximately 70% 1-butanol, 15% 1-hexanol, and 5% 1-octanol by mass, resulting in a cetane number around 18. In order to achieve mixing-controlled compression ignition with GrenOl, an exhaust rebreathing strategy is employed. In this strategy, the exhaust valve reopens for a part of the intake stroke, inducting hot exhaust into the cylinder and preheating the fresh air. This study investigates the feasibility of operating with such a valve strategy from idle to peak torque. At idle, the primary challenge is ensuring stable combustion by inducting adequate exhaust to achieve ignition. Under load, when cylinder temperatures are higher, the primary challenge is ensuring sufficient air is inducted to achieve the target torque. It was found
Trzaska, JosephXu, ZhihaoBoehman, André L.
A consequence of the automotive industry's shift to electrification is that a significantly higher percentage of a vehicle's lifecycle CO2 emissions occur during the production phase. As a result, vehicle manufacturers and suppliers must shift the focus of product development from the 'in-use phase only' to optimizing the complete product lifecycle. The proper design of a battery has the highest impact to all other phases following in the life cycle. It influences the selection of materials, the manufacturing, in-use and end of life, respectively the recycling and recycling yield for a circular economy. Using real-life examples, the paper will explain what the main parameters are necessary for designing a sustainable battery. What are the low hanging fruits to be considered? In addition, it will elaborate on the relation as well as the impacts to other KPIs like safety, costs and lifetime of the battery. Finally, it will round up in an outlook on how batteries will evolve in the future
Braun, AndreasRothbart, Martin
A cutting-edge EV powertrain NVH laboratory has been established at Dana Incorporated’s world headquarters in Ohio, significantly enhancing its capabilities in EV powertrain NVH development. This state-of-the-art, industry-leading facility is specifically designed to address diverse NVH requirements for EV powertrain development and validation processes. This capability substantially reduces development time for new drivetrain systems. Key features of the laboratory include a hemi-anechoic chamber, two AC asynchronous load motors, an acoustically isolated high-speed input motor, and two battery emulators capable of accommodating both low and high-voltage requirements. The NVH laboratory enables engineers to evaluate system performance and correlate results with digital twin models. This capability supports the optimization of NVH characteristics at both the system and component levels, as well as the refinement of CAE models for enhanced design precision. This paper details the design
Cheng, Ming-TeZugo, Chris
Electric vehicles (EVs) are shaping the future of mobility, with drive motors serving as a cornerstone of their efficiency and performance. Motor testing machines are essential for verifying the functionality of EV motors; however, flaws in testing equipment, such as gear-related issues, frequently cause operational challenges. This study focuses on improving motor testing processes by leveraging machine learning and vibration signal analysis for early detection of gear faults. Through statistical feature extraction and the application of classifiers like Wide Naive Bayes and Coarse Tree, the collected vibration signals were categorized as normal or faulty under both loaded (0.275 kW) and no-load conditions. A performance comparison demonstrated the superior accuracy of the wide neural networks algorithm, achieving 95.3%. This methodology provides an intelligent, preventive maintenance solution, significantly enhancing the reliability of motor testing benches.
S, RavikumarSharik, NSyed, ShaulV, MuralidharanD, Pradeep Kumar
As the automotive industry transitions to electrification, understanding the differences in ambient operating vibration environments between conventional internal combustion engine (ICE) propulsion systems, battery electric vehicles (BEVs), and hybrid electric vehicles (HEVs) becomes increasingly important. Many automotive vibration testing standards provide frequency and amplitude test levels based on historical ICE vehicle data. Some standards note the potential inaccuracies of using this data source to test BEVs/HEVs and recommend using field-recorded data, if possible, while others make no note. Preliminary comparisons of BEV, HEV, and ICE vehicle ambient operating vibration environments show variations due to battery cell pack weight and engine vibration, among other factors. As accurate testing is tantamount to vehicle safety and longevity, the automotive testing industry must confirm the suitability of current test standards for BEVs and HEVs or create new ones. This paper
Achatz, TomStoll, Cherie
Bearings are fundamental components in automotive systems, ensuring smooth operation, efficiency, and longevity. They are widely used in various automotive systems such as wheel hubs, transmissions, engines, steering systems etc. Early detection of bearing defects during End-of-Line (EOL) testing and operational phases is crucial for preventive maintenance, thereby preventing system malfunctions. In the era of Industry 4.0, vibrational, accelerometer, and other IoT sensors are actively engaged in capturing performance data and identifying defects. These sensors generate vast amounts of data, enabling the development of advanced data-driven applications and leveraging deep learning models. While deep learning approaches have shown promising results in bearing fault diagnosis, they often require extensive data, complex model architectures, and specialized hardware. This study proposes a novel method leveraging the capabilities of Vision Language Models (VLMs) and Large Language Models
Chandrasekaran, BalajiCury, Rudoniel
For years the NVH community has known that openings in the dash sheet metal, such as holes to pass wire harnesses through, creates an acoustical weak point that limits the potential noise reduction of the dash insulation system. These pass-throughs can also be a source of water leaks into the vehicle’s interior. With internal combustion engines and now electric inverter power plants generating significant high frequency sound, the need to seal this area is vital. By molding a lightweight barrier that draws through the fiber/absorber interior decoupler and dash sheet metal which mates to a secondary seal molded into an outer engine dash decoupler, the two opposing molded barriers meet in the engine compartment and compress together forming a seal around the wire harness. This male/female molded seal replaces the conventional snap in grommet and eliminates noise/water leaks. The system Sound Transmission Loss (STL) is equivalent to similarly insulated sheet metal with no holes
Check, JamesMoritz, Charles
When the ambient temperature is too low, the performance of the lithium-ion battery will deteriorate, and the car will have the problems of difficult charging, fast power consumption, and even difficult to start, so the battery needs to be heated before use to provide a comfortable working environment for the lithium-ion. The high-frequency pulse heating system can quickly and evenly raise the temperature of the battery, but there is noise during operation, which affects the NVH performance of the vehicle itself, and its noise comfort needs to be further optimized. Firstly, the high-frequency pulse heating system is discussed in detail, and the parameters affecting the NVH performance are explored. Secondly, NVH tests and subjective and objective evaluations were carried out based on different system parameters, relevant data were collected to establish a model, the influence degree of each parameter was demonstrated, and the best parameter combination was determined. Finally, the
Yun, ZhaoShouhui, HuangHu, ZhongxunHui, HuiZhou, ChangshuiTeng, Charlie
The automotive industry continues to develop new powertrain and vehicle technologies aimed at reducing overall vehicle-level fuel consumption. While the use of electrified propulsion systems is expected to play an increasingly important role in helping OEMs meet fleet CO2 reduction targets, hybridized propulsion solutions will continue to play a vital role in the electrification strategy of vehicle manufacturers. Plug-in hybrid electric vehicles (PHEV) and range extender vehicles (REx) come with unique NVH challenges due to their different possible operation modes. First, the paper outlines different driveline and vehicle architectures for PHEV and REx. Given the multiple general architectures, as well as operation modes which typically accompany these vehicles, NVH characterizations and noise source-path analysis can be more complicated than conventional vehicles. In the following steps, typical NVH related challenges are highlighted and potential solutions for NVH optimization are
Wellmann, ThomasFord, AlexPruetz, Jeffrey
This SAE Recommended Practice outlines labeling guidelines and performance requirements for printed information and warning labels used on components, subsystems, and systems. It covers content, placement, and durability requirements throughout the product life cycle, from initial production to recycling or disposal.
Battery Tape and Label Committee
This paper presents a comparative analysis of various short-time current rating formulas, focusing on applications in aircraft wiring. Examining historical formulas developed by pioneers such as W.H. Preece and I.M. Onderdonk alongside modern experimental data provide a comprehensive understanding of short-time current rating formulas. Also, exploring key challenges, such as environmental conditions and material variability in aviation with particular attention to adiabatic methods for current-carrying calculations. The findings of this paper offer practical insights into improving the safety and reliability of an aircraft electrical system with improving the accuracy of short-time current rating predictions.
Fifield, Jon
The growing demand for air transport requires efficient and sustainable power systems to meet the pressing need for decarbonizing the sector. A hybrid unit, consisting of a proton exchange membrane fuel cell system and a lithium-ion battery, is a suitable option due to the advantages of reduced gravimetric and volumetric impacts, along with the flexibility of energy management strategies. This work addresses, using a model-based approach, the issue of integrating these electrochemical devices into the aircraft’s electrical architecture considering both design and energy management aspects. A literature derived DC-DC converter bi-dimensional power map is exploited to investigate scenarios differentiated by the fuel cell system power rating and number of stacks working in parallel such that the DC bus line voltage requirements can be respected. These maps relate the converter’s maximum deliverable power to the input and desired output voltage. The combined design and energy management
Aliberti, PaoloSorrentino, MarcoCuomo, FabrizioNapolitano, Ciro
The goal of the development of an electric aircraft engine is to create an aircraft system that achieves ultimate efficiency using hydrogen fuel instead of fossil fuels. Therefore, it is necessary to focus on reducing weight as much as possible, and this paper describes the approach to such fuel cell-powered aircraft. The authors have adopted a superconducting coreless rotating electric machine with an integrated hydrogen tank and are pursuing a target of 70kg or less for the main components of a 2MW rotating electric machine. High-temperature superconducting cables have zero electrical resistance and can carry a very high current density, but the alternating current (AC) loss generated when used in AC has been an issue in their application to rotating electric machines. In 2023, The SCSC cable was developed to be a low-AC-loss, robust, and high current cable concept, in which copper-plated multifilament coated conductors are wound spirally on a core. In addition to using this
Oyori, HitoshiSakurai, ShoKusase, ShinYoshida, YukihiroYoshinaga, SeiichiroNose, HiroyukiAmemiya, Naoyuki
Industrial bearings are critical components in aerospace, industrial, and automotive manufacturing, where their failures can result in costly downtime. Traditional fault diagnosis typically depends on time-consuming on-site inspections conducted by specialized field engineers. This study introduces an automated Artificial Intelligence virtual agent system that functions as a maintenance technician, empowering on-site personnel to perform preliminary diagnoses. By reducing the dependence on specialized engineers, this technology aims to minimize downtime. The Agentic Artificial Intelligence system leverages agents with the backbone of intelligence from Computer Vision and Large Language Models to guide the inspection process, answer queries from a comprehensive knowledge base, analyze defect images, and generate detailed reports with actionable recommendations. Multiple deep learning algorithms are provisioned as backend API tools to support the agentic workflow. This study details the
Chandrasekaran, Balaji
The authors have witnessed a notable surge in the number of designs and in the guidance material for electric and hybrid aircraft. FAA and EASA have continued to evaluate the safety of Propulsion Battery Systems (PBS), with a focus on thermal runaway containment testing. As a result, a harmonization white paper [7] was issued to provide a certification path for Thermal Runaway (TR) Hazards, followed by an EASA certification memorandum on the acceptable approaches for the certification of Electric/Hybrid Propulsion Systems (EHPS). Recently, an FAA Advisory Circular (draft) was issued for the “powered-lift” aircraft that feature these propulsion battery systems. Despite the advances made by electric/hybrid aircraft manufacturers and the aviation authorities, there is still a missing piece of the puzzle. Mainly, engineering work still needs to be done to properly integrate the EHPS architecture to achieve safety objectives. The burden is still on systems engineering to propose their own
Hanna, MichaelWalker, Cherizar
This standard is applicable to the marking of aerospace vehicle electrical wires and cables using ultraviolet (UV) lasers. This standard specifies the process requirements for the implementation of UV laser marking of aerospace electrical wire and cable and fiber-optic cable to achieve an acceptable quality mark using equipment designed for UV laser marking of identification codes on aerospace wire and cable. Wiring specified as UV laser markable subject to AS4373 and which has been marked in accordance with this standard will conform to the requirements of AS50881.
AE-8A Elec Wiring and Fiber Optic Interconnect Sys Install
A Northwestern University-led team of researchers has developed a new fuel cell that harvests energy from microbes living in dirt. About the size of a standard paperback book, the completely soil-powered technology could fuel underground sensors used in precision agriculture and green infrastructure. This potentially could offer a sustainable, renewable alternative to batteries, which hold toxic, flammable chemicals that leach into the ground, are fraught with conflict-filled supply chains and contribute to the ever-growing problem of electronic waste.
The efficiency and performance of lithium-ion batteries are highly influenced by the quality of laser cutting of electrode materials. The laser cut quality of thin foils is often measured by amount of kerf width and heat-affected zone (HAZ). This article adopts a novel approach that involves pre-cooling of thin copper foils prior to the laser cutting process. The impact of laser conditions and foil temperature were analyzed on HAZ and kerf width induced during laser cutting experiments conducted based on L27 orthogonal array. Teaching–learning–based optimization (TLBO) technique was employed to identify the optimal laser parameters. ANOVA results indicated that the temperature was the most significant factor influencing kerf width and HAZ. The optimized laser parameters identified through TLBO technique were 16 W laser power, 69.47 mm/s scanning speed, and 20 kHz pulse frequency at dry ice conditions. A reduction of 50.76% kerf width and a decrease in 7.6% HAZ were observed when the
Rao, Akshay P.Bharatish, A.Solaiachari, SivakumarKumar, S. Mahendra
AS5653 may be applied to Air Vehicles and Stores implementing MIL-STD-1760 Interface Standard for Aircraft/Store Electrical Interconnection System.
AS-1A Avionic Networks Committee
This SAE Aerospace Standard (AS) contains requirements for a digital time division command/response multiplex data bus, for use in systems integration that is functionally similar to MIL-STD-1553B with Notice 2 but with a star topology and some deleted functionality. Even with the use of this document, differences may exist between multiplex data buses in different system applications due to particular application requirements and the options allowed in this document. The system designer must recognize this fact and design the multiplex bus controller (BC) hardware and software to accommodate such differences. These designer selected options must exist to allow the necessary flexibility in the design of specific multiplex systems in order to provide for the control mechanism, architectural redundancy, degradation concept, and traffic patterns peculiar to the specific application requirements.
AS-1A Avionic Networks Committee
Improving electric vehicles’ overall thermal management strategy can directly or indirectly improve battery efficiency and vehicle range [1]. In this study, the effect of the coolant type used in BTMS (battery thermal management system) units used for heating batteries in cold weather conditions was investigated in electric buses. In this investigation, tests were performed with two types of antifreeze, which have different characteristics. The study evaluated the impact of coolant flow, BTMS circulation pump performance, and battery heating using these two types of antifreeze in the BTMS coolant line. In addition to carrying out tests, 1D computational fluid dynamics models’ simulations were carried out for both types of antifreeze, and the results were validated with experimental findings. In this study, a 12-m EV Citivolt vehicle of Anadolu Isuzu was used for tests. As a result, it was observed that differences in the properties of the antifreeze that is used in BTMS coolant line
Çetir, ÖzgürBirgül, Çağrı Emre
This document was prepared by the SAE AS-1A2 Committee to establish techniques for verifying that Network Controllers (NCs), Network Terminals (NTs), switches, cables, and connectors comply with the physical layer requirements specified in AS5653B. Note that this verification document only verifies the specific requirements from AS5653B and does not verify all of the requirements invoked by documents that are referenced by AS5653B. The procuring authority may require further testing to verify the requirements not explicitly defined in AS5653B and in this verification document.
AS-1A Avionic Networks Committee
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