Browse Topic: Electric power

Items (2,091)
In this study, vibration characteristics inside an electric power unit at gravity center where direct measurement is impossible were estimated by using virtual point transformation to consider guideline for effective countermeasures to the structure or generated force characteristics inside the power source. Vibration acceleration, transfer function and the generated force in operation at the gravity center of the electrical power source were obtained by vibration characteristics at around the power source which can be measured directly. In addition, the transfer functions from the gravity center to the power source attachment points on the product were also estimated. And then, the contribution from the gravity center to the power unit attachment point was obtained by multiplying generated force with the transfer function. As results, the obtained total contribution was almost same with the actual measured vibration at the attachment point. Furthermore, the rotational contribution
Kubo, RyomaHara, KentaYoshida, Junji
Based on the harmonic current injection method used to suppress the torsional vibration of the electric drive system, the selection of the phase and amplitude of the harmonic current based on vibration and noise has been explored in this paper. Through the adoption of the active harmonic current injection method, additional torque fluctuations are generated by actively injecting harmonic currents of specific amplitudes and phases, and closed-loop control is carried out to counteract the torque fluctuations of the motor body. The selection of the magnitude of the injected harmonic current is crucial and plays a vital role in the reduction of torque ripple. Incorrect harmonic currents may not achieve the optimal torque ripple suppression effect or even increase the motor torque ripple. Since the actively injected harmonic current is used to counteract the torque ripple caused by the magnetic flux linkage harmonics of the motor body, the target harmonic current command is very important
Jing, JunchaoZhang, JunzhiLiu, YiqiangHuang, WeishanDai, Zhengxing
Polymer Electrolyte Membrane Fuel Cells (PEMFCs) recently received a relevant interest as an electric power generation technology in Fuel Cells Electric Vehicles (FCEVs) to decarbonize hard-to-abate sectors as a complement to Battery Electric Vehicles (BEVs). However, the massive requirements of power and durability indicate the urgent need to develop higher-than-ever power density designs with minimum internal gradients to mitigate degradation, discarding sub-optimal designs since the early design stage. Starting from the outcomes of a first study, confirming that for industry-relevant PEMFCs the parallel channel flow field was the only archetype able to minimize jointly pressure losses and limiting super-saturation at high current density, still several degrees of freedom exist for the cell designer. In this study, the research of the optimal PEMFC design is fine-tuned using a CAE-guided design process. Candidate solutions are explored using an optimization software and solving for
Rossi, EdoardoCroci, FedericoMartoccia, LorenzoCicalese, GiuseppeD'Adamo, Alessandro
Reducing emissions in individual transport requires electrification and hybridization. Emission reduction depends on the degree of electrification, the specific powertrain design and optimized components. This is especially true for hybrids with the highest number of components, consisting of combustion engine, transmission, electric motors and batteries. The integration of the electric motor in the transmission for dedicated hybrid transmissions leads to many possible concepts. Computer-aided powertrain synthesis is therefore needed to develop new powertrain architectures. In a publicly funded project, we have developed a powertrain synthesis that includes a combustion engine synthesis and a transmission synthesis. In this paper we focus on the impact of the engine concept on the powertrain dimensioning, fuel consumption, performance and operating behavior in a parallel hybrid configuration. In addition to different engine concepts, the electrical power is also varied to discuss the
Sturm, AxelHenze, RomanKüçükay, FeritWolgast, CarstenEilts, Peter
In the United States (US), the off-road sector (i.e., agriculture, construction, etc.) contributes to approximately 10% of the country’s transportation greenhouse gas (GHG) emissions, similar to the aviation sector. The off-road sector is extremely diverse; as the EPA MOVES model classifies it into 11 sub-sectors, which include 85 different types of equipment. These equipment types have horsepower ranging from 1 to greater than 3000 and have very different utilization, which makes decarbonization a complex endeavor. To address this, Argonne’s on-road vehicle fleet model, VISION, has been expanded to the off-road sector. The GHG emission factors for several energy carriers (biofuels, electricity, and hydrogen) have been incorporated from Argonne’s GREET model for a sector-wide well-to-wheel (WTW) GHG emissions analysis of the present and future fleet. Several technology adoption and energy decarbonization scenarios were modeled to better understand the appropriate actions required to
Tripathi, ShashwatKolodziej, ChristopherGohlke, DavidBurnham, AndrewZhou, YanLongman, Douglas
Electrifying truck fleets has the potential to improve energy efficiency and reduce carbon emissions from the freight transportation sector. However, the range limitations and substantial capital costs with current battery technologies imposes constraints that challenge the overall cost feasibility of electrifying fleets for logistics companies. In this paper, we investigate the coupled routing and charge scheduling optimization of a delivery fleet serving a large urban area as one approach to discovering feasible pathways. To this end, we first build an improved energy consumption model for a Class 7-8 electric and diesel truck using a data-driven approach of generating energy consumption data from detailed powertrain simulations on numerous drive cycles. We then conduct several analyses on the impact of battery pack capacity, cost, and electricity prices on the amortized daily total cost of fleet electrification at different penetration levels, considering availability of fast
Wendimagegnehu, Yared TadesseAyalew, BeshahIvanco, AndrejHailemichael, Habtamu
Sustainable aviation fuels are becoming more widely available for current and future engine powered propulsion systems. However, the diversity of ignition behavior in these fuels poses a challenge to achieving robust, efficient operation. Specifically, low cetane fuels with poor ignitability exhibit highly variable torque production unless fuel is injected earlier during compression. The tradeoff is that earlier injection may cause dangerously high in-cylinder pressure rise rates. Novel models that can simulate these competing behaviors are needed so that appropriate strategies may be developed for controlling combustion at low cetane fueling conditions. This work builds upon a previously developed model that simulates asymmetric combustion phasing (CA50) distributions as a function of fuel cetane, fuel injection timing, and electrical power supplied to an in-cylinder thermal ignition assist device. An extension of the model is presented in which the phasing output is used to
Ahmed, OmarMiddleton, RobertStefanopoulou, AnnaKim, KennethKweon, Chol-Bum
As the first pure electric flagship sedan under the Geely Galaxy brand, a challenging aerodynamic target was set at the early stage of Geely Galaxy E8 for reducing electric power consumption and improving vehicle range. In response, the aerodynamic team formulated a detailed development plan and an overall drag reduction strategy. After conducting numerous loops of simulations and wind tunnel tests, along with continuous cross-disciplinary communication and collaboration, a product with outstanding aerodynamic performance was successfully developed. During the aerodynamic development of the E8, the primarily utilized steady-state simulations sometimes revealed significant discrepancies when compared to wind tunnel test results, particularly in schemes such as the air curtain, aerodynamic rims, and rear light feature optimizations. Some trends were even contradictory. Further investigations demonstrated that unsteady simulation methods captured different flow field information
Li, QiangLiu, HuanYang, TianjunLiang, ChangqiuZhu, ZhenyingLiao, Huihong
This SAE Aerospace Standard (AS) establishes the minimum performance standards for equipment used as secondary alternating current (AC) electrical power sources in aerospace electric power systems.
AE-7B Power Management, Distribution and Storage
The selection of the key components of proton exchange membrane fuel cell (PEMFC) crucially impacts the performance. This work developed a model of the fuel cell system model to simulate the power consumption of component and system and the temperature dynamic response of stack in real systems. A PEMFC simulation model was developed based on AMESim, encompassing the air supply subsystem, hydrogen supply subsystem, and the hydrothermal management subsystem. The parameters for the flow and pressure of hydrogen, air, and water were established based on the operational requirements to ensure efficient stack performance. Furthermore, a PID control model was employed to regulate the flow and pressure parameters of hydrogen, air, and water, in accordance with the operational requirements, to ensure optimal PEMFC system performance.The purpose of this study is to predict the power consumption of the key components and the overall system, as well as to analyze the compliance with fuel supply
Yu, PeiwenWang, YanboZhao, XiaojunPan, FengwenShi, BaofanYang, FengQiao, XingnianShan, FengxiangCheng, XiaoxianZhang, YaranZhang, ChunSun, YulingGao, YongFeng, Gang
With the increase in vehicle population, the environmental problems caused by excessive carbon emissions from vehicles are becoming increasingly serious. Currently, China is actively promoting the development of electric vehicles to reduce carbon emissions. However, the electricity used by electric vehicles is a secondary energy source, and thermal power generation still dominates China's current power structure, so electric vehicles will indirectly contribute to carbon emissions during use. Calculating and analysing the carbon emissions of fuel vehicles and electric vehicles will give a better idea of the environmental advantages of electric vehicles. In this paper, the World Light Vehicle Test Cycle (WLTC) are selected, and the energy consumption is calculated by the energy consumption formula of fuel and electric vehicles under different conditions, and the carbon emission is obtained by the carbon emission coefficients of gasoline and electric energy. Through MATLAB calculation
Xie, HaonanLin, Guangyu
The inductance parameter is important for the flux regulation performance of the hybrid excitation motor, and the axial structure leads to the change in the inductance parameter of the axial-radial hybrid excitation motor (ARHEM). To clarify the inductance characteristic of the ARHEM with different winding construction and the mutual coupling effect between the axial excitation and permanent magnet excitation on the inductance. Firstly, the structure of the ARHEM is presented. Secondly, the self and mutual inductance characteristics of ARHEM are analyzed using the winding function method. Then, the influence of the axial excitation structure on the armature reaction field and saliency ratio of ARHEM. On this basis, the mechanism of the mutual coupling, between the axial excitation and permanent magnet field under different excitation currents on the main air gap magnetic field, and the inductance of ARHEM with fractional slot are revealed.
Fu, DongXueZhao, HeweiWu, QiminYuan, ChunweiWang, DongQiu, Hongbo
The integration of phase change materials (PCMs) with thermoelectric generators (TEGs) presents a solution to the challenge of unstable output resulting from fluctuations in the heat source. This study involved the establishment of an experimental test setup for PCM-TEG system to examine the impact of heat source power on the thermoelectric performance of PCM-TEG system. The results suggest that incorporating PCM effectively mitigates output voltage fluctuations, while higher heating power levels correspond to a notable extension in effective operational duration. In situations of low heat source power, incomplete PCM melting may lead to a significant decline in electricity generation during non-heating stages. Notably, the electricity generation during non-heating stages at 90 W heating power surpasses that at 30 W heating power by a factor of 11.78. Furthermore, the electricity generated during non-heating stages contributes to 22.4% of the total electricity generation. These
Tian, MengWu, FengyuZuo, AoXuan, ZhiweiZhao, Yulong
This paper proposes a theoretical drive cycle for the competition, considering the battery pack project under design. The vehicle has a non-reversible, double-stage gear train, created without a dynamic investigation. To evaluate the effect on performance, several ratios were analyzed. Dynamic model uses Eksergian’s Equation of Motion to evaluate car equivalent mass (generalized inertia), and external forces acting on the vehicle. The circuit is divided into key locations where the driver is likely to accelerate or brake, based on a predicted behavior. MATLAB ODE Solver executed the numerical integration, evaluating time forward coordinates, creating the drive cycle. Linear gear train results provided data as boundary conditions for a second round of simulations performed with epicyclic gear trains. Model is updated to include their nonlinearity by differential algebraic equation employment with Lagrange multipliers. All data undergoes evaluation to ascertain the mechanical and
Rodrigues, Patrícia Mainardi TortorelliSilveira, Henrique Leandro
It’s common knowledge that a major challenge for solar energy is how to store excess energy produced when conditions are right, like noon-time sun, so that it can be used later. The usual answer is batteries. But renewable energy resources are causing problems for the electricity grid in other ways as well. In a warm, sunny location like California, mid-afternoon had been a time of peak demand for the electric utility, but with solar it’s now a time of peak output.
In the future, power sockets used to recharge smartphones, tablets, and laptops could become obsolete. The electricity would then come from our own clothes. By means of a new polymer that is applied on textile fibers, clothing could soon function as solar collectors and thus as a mobile energy supply.
The Korea Research Institute of Standards and Science (KRISS) has developed a metamaterial that traps and amplifies micro-vibrations in small areas. This innovation is expected to increase the power output of energy harvesting, which converts wasted vibration energy into electricity, and accelerate its commercialization.
This document provides recommended best practice methods and processes for the in-service inspection, evaluation and cleaning of all physical contact (PC) fiber optic interconnect components (termini, alignment sleeves and connectors), test equipment and test leads for maintainers qualified to the approved aerospace fiber optic training courses developed in accordance with ARP5602 or ARINC807. This document also provides a decision-making disposition flowchart to determine whether the fiber optic components are acceptable for operation. For definitions of individual component parts refer to ARP5061.
AS-3 Fiber Optics and Applied Photonics Committee
As the U.S. military embraces vehicle electrification, high-reliability components are rising to the occasion to support their advanced electrical power systems. In recent years, electronic device designers have started using wide band-gap (WBG) materials like silicon carbide (SiC) and gallium nitride (GaN) to develop the semiconductors required for military device power supplies. These materials can operate at much higher voltages, perform switching at higher frequencies, and feature better thermal characteristics. Compared to silicon, SiC-based semiconductors provide superior performance. The growing availability of these materials, in terms of access and cost, continues to encourage electrification. With the ever-present pressure of size, weight, and power (SWaP) optimization in military applications, and a desire to keep up with the pace of innovation, there's a need for capacitors that can deliver higher power efficiency, switching frequency, and temperature resistance under harsh
Sustainable mobility is a pressing challenge for modern society. Electrification of transportation is a key step towards decarbonization, and hydrogen Fuel Cell Hybrid Electric Vehicles (FCHEVs) offer a promising alternative to Battery Electric Vehicles (BEVs), especially for long-range applications: they combine a battery system with a fuel cell, which provides onboard electric power through the conversion of hydrogen. Paramount importance is then given to the design and sizing of the hybrid powertrain for achieving a compromise between high performance, efficiency, and low cost. This work presents a Hardware-in-the-Loop (HIL) platform developed for designing and testing the powertrain layout of an FCHEV. The platform comprises two systems: a simulation model reproducing the dynamics of a microcar and a hardware system for the fuel cell hybrid electric powertrain. The former simulates the vehicle's behavior, while the latter is composed of a 2kW real fuel cell stack and a 100Ah Li-ion
Bartolucci, LorenzoCennamo, EdoardoCordiner, StefanoDonnini, MarcoGrattarola, FedericoMulone, Vincenzo
The aim of paper is to present the workflow of battery sizing for electric L7e-CU type vehicle. The intention is to use it as last-mile delivery multi-purpose vehicle. Based on legislation limits and pursuing the real-world driving cycle, major vehicle characteristics as total vehicle mass including payload and wheel size are determined. Vehicle total energy consumption is calculated knowing vehicle power in time. Accordingly, to selected gearbox ratio the electric motor nominal power-speed curve is defined as well as the nominal torque-speed curve. Applying vehicle acceleration dynamics involving limits considering resistive forces, acting on the vehicle, e.g. slope, friction, air drag, and total inertia, referred to the electric motor through the gearbox the electric motor over-load-ability characteristics are calculated. Next, the motor design is defined and optimized. Defining required vehicle range at given driving cycle and knowing the vehicle and all powertrain characteristics
Rupnik, UrbanVukotić, MarioManko, RomanAlić, AlenČorović, SelmaMiljavec, Damijan
To expand the availability of electricity generated from nuclear power, several countries have started developing designs for small modular reactors (SMRs), which could take less time and money to construct compared to existing reactors.
Penn Engineers have developed a new chip that uses light waves, rather than electricity, to perform the complex math essential to training AI. The chip has the potential to radically accelerate the processing speed of computers while also reducing their energy consumption.
Solar panels are an increasingly popular way to generate electricity from the sun’s energy. Although humans are still figuring out how to reliably turn that energy into fuel, plants have been doing it for eons through photosynthesis. Now, a team reporting in ACS Engineering Au has mimicked the process to produce methane, an energy-dense fuel, from carbon dioxide, water and sunlight. Their prototype system could help pave the way toward replacing nonrenewable fossil fuels.
The automotive PowerNet is in the middle of a major transformation. The main drivers are steadily increasing power demand, availability requirements, and complexity and cost. These factors result in a wide variety of possible future PowerNet topologies. The increasing power demand is, among other factors, caused by the progressive electrification of formerly mechanical components and a constantly increasing number of comfort and safety loads. This leads to a steady increase in installed electrical power. X-by-wire systems1 and autonomous driving functions result in higher availability requirements. As a result, the power supply of all safety-critical loads must always be kept sufficiently stable. To reduce costs and increase reliability, the car manufacturers aim to reduce the complexity of the PowerNet system, including the wiring harness and the controller network. The wiring harness e.g., is currently one of the most expensive parts of modern cars. These challenges are met with a
Jagfeld, Sebastian Michael PeterWeldle, RichardKnorr, RainerFill, AlexanderBirke, Kai Peter
With the COP28 decisions the world is thriving for a future net-zero-CO2 society and the and current regulation acts, the energy infrastructure is changing in direction of renewables in energy production. All industry sectors will extend their share of direct or indirect electrification. The question might arise if the build-up of the renewables in energy production is fast enough. Demand and supply might not match in the short- and mid-term. The paper will discuss the roadmaps, directions and legislative boundary parameter in the regenerative energy landscape and their regional differences. National funding on renewables will gain an increasing importance to accelerate the energy transformation. The are often competing in attracting the same know-how on a global scale. In addition the paper includes details about energy conversion, efficiency as well as potential transport scenarios from production to the end consumer. Technologies are compared in respect of their TLR level and
Rothbart, Martin
Dynamic wireless charging (DWC) systems can make up electrified roads (eRoads) on which electricity from the grid is supplied to electric vehicles (EVs) wirelessly while the EVs travel along the roads. Electrification of roads contributes to decarbonizing the transport sector and offers a strong solution to high battery cost, range anxiety, and long charging times of EVs. However, the DWC eRoads infrastructure is costly. This article presents a model to minimize the infrastructure cost so that the deployment of eRoads can be economically more feasible. The investment for eRoad infrastructure consists of the costs of various components including inverters, road-embedded power transmitter devices, controllers, and grid connections. These costs depend on the traffic flow of EVs. The configuration and deployment strategy of the proposed eRoads in Southeastern Canada are designed with optimized charging power and DWC coverage ratio to attain the best cost-effectiveness. Well-designed
Qiu, KuanrongRibberink, HajoEntchev, Evgueniy
The purpose of the Air Generation System is to provide a constant supply of conditioned fresh air to meet the necessary oxygen availability and to prevent CO2 concentrations for the occupants in an aircraft. The engine bleed energy or electrical load energy consumed towards this circumstance accounts to be approximately 5% of total fuel burn and in turn, contributes to the global emissions of greenhouse gases. This paper studies the improvement areas of the present conventional system such as fuel burn consumption associated with an aircraft ECS depending on the amount of bleed, ram air usage and electric power consumption. Improved systems for sustainability and hybridization in environmental control systems are desirable in aircraft. This paper explains how a new design of the sustainable hybrid module assists the conventional system, by using a proposed modular MPBR. The MPBR system generates oxygen-enriched air, which is mixed with the traditional fresh air generated from
Subrahmanya, ShreeshaKumar, NaveenRanjan, JayantKotnadh, Shivaprasad
A new electrical power converter design achieves a much higher efficiency at lower cost and maintenance than before. The direct current voltage boost converter is poised to be a significant contribution to the further development of improved electric and electronic components for healthcare devices.
Opposed piston two-stroke (OP2S) diesel engines have demonstrated a reduction in engine-out emissions and increased efficiency compared to conventional four-stroke diesel engines. Due to the higher stroke-to-bore ratio and the absence of a cylinder head, the heat transfer loss to the coolant is lower near ‘Top Dead Center.’ The selection and design of the air path is critical to realizing the benefits of the OP2S engine architecture. Like any two-stroke diesel engine, the scavenging process and the composition of the internal residuals are predominantly governed by the pressure differential between the intake and the exhaust ports. Without dedicated pumping strokes, the two-stroke engine architecture requires external devices to breathe. In the unique OP2S engine architecture studied in this work, the external pumping devices present in the air path include an electrically assisted turbocharger (EAT), an electrified EGR pump, and a back-pressure valve (BPv) located downstream of the
Bhatt, AnkurGandolfo, JohnHuo, MingGainey, BrianLawler, Benjamin
Bhutan is a small nation in the eastern Himalayas, between two of the world's largest neighbors and fastest-growing economies; China, and India. The GDP of the country is $2.707 Billion as of 2022. Bhutan’s largest renewable source is hydropower, which has a known potential of 30,000 MW. However, it has only been able to harvest only 1,480 MW (5% of the potential). The current overall electrification rate is 99% overall with 98.4% in rural areas. It exports 75.5% of total electricity generated in the country to India. However, the reliable supply of electricity remains a big challenge. The government is also pushing the use of renewable energy sources like solar and wind to diversify the energy mix and enhance the power security of the country. The share of renewable energy is very minimal at present amounting to 723 kW Solar PV and 600 kW Wind power. Bioenergy in the form of fuel wood, energy crops & crop residues, and cattle dung has great potential in the country as the country’s
Wangchuk, SingyeKumar, Naveen
The 2023 FISITA White Paper (for which the author was a contributor) on managing in-service emissions and transportation options, to reduce CO2 (CO2-e or carbon footprint) from the existing vehicle fleet, proposed 6 levers which could be activated to complement the rapid transition to vehicles using only renewable energy sources. Another management opportunity reported here is optimizing the vehicle’s life in-service to minimize the life-cycle CO2 impact of a range of present and upcoming vehicles. This study of the US vehicle fleet has quite different travel and composition characteristics to European (EU27) vehicles. In addition, the embodied CO2 is based on ANL’s GREET data rather than EU27 SimaPro methodology. It is demonstrated that in-service, whole-of-life mileage has a significant influence on the optimum life cycle CO2 for BEVs and H2 fuelled FCEVs, as well as ICEs and PHEVs. Thus, the object is to show how much present, typical in-service life-mileage differs from the
Watson, Harry C.
The present study was motivated by a need to expand information for consumers offered through the FuelEconomy.Gov website. To that end, a power-based modeling approach has been used to examine the effect of steady-speed driving on estimated range for model year 2020 – 2023 battery electric vehicles (BEVs). This approach allowed rapid study of a broader range of BEV models than could be accomplished through vehicle tests. Publicly accessible certification test results and other data were used to perform a regression between cycle-average tractive power requirements and the resulting electrical power. This regression enabled estimation of electric power and energy use over a range of steady highway speeds. These analyses in turn allowed projection of vehicle range at differing speeds. The projections agree within 6% with available 65 MPH manufacturer test data. Analyses of vehicles from model years 2020 – 2023 show that the 5-cycle range and energy use values from the window stickers of
Sluder, C. ScottDavis, Stacy C.Boundy, Robert G.
Toyota has developed a new 2.4L L4 turbo (2.4L-T) engine with 8AT and 1-motor hybrid electric powertrains for midsize pickup trucks. The aim of these powertrains is to fulfill both strict fuel economy and emission regulations toward “Carbon Neutrality”, while exceeding customer expectations. The new 2.4L L4 turbocharged gasoline engine complies with severe Tier3 Bin30/LEVIII SULEV30 emission regulations for body-on-frame midsize pickup trucks improving both thermal efficiency and maximum torque. This engine is matched with a newly developed 8-speed automatic transmission with wide range and close step gear ratios and extended lock-up range to fulfill three trade-off performances: powerful driving, NVH and fuel economy. In addition, a 1-motor hybrid electric version is developed with a motor generator and disconnect clutch between the engine and transmission. This hybrid architecture provides EV driving, which enhances the NVH and fuel economy, and provides additional acceleration with
Endo, MotoshiroBridge, AlistairIkeda, AkihiroMiyamoto, KoichiMiyazaki, TerufumiHosoda, FuminoriHerring, CraigWallace, James J.Hu, Mu
This Electric Road System was devised that would provide electric power to EVs directly from the infrastructure so that EVs could undergo intermittent charging while driving. This system is a conductive dynamic charging system that operates from the side of the vehicle (roadside), and research has been underway on the application of this approach to passenger cars and race cars. This paper focused on resolving issues with freight vehicles, which account for most of the CO2 emissions in the transportation sector. This Electric Road System that operates by contact from the roadside was applied to heavy-duty trucks, which have been considered a challenge to convert to EVs, and at the same time the infrastructure technology was also expanded and evolved. And verification tests using actual vehicles were conducted for regenerative energy absorption control of a charging vehicle while driving. The results confirmed that this control system appropriately controls the distribution of power
Tajima, TakamitsuAbe, Hiroyuki
Researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have invented and patented a new cathode material that replaces lithium ions with sodium and would be significantly cheaper. The cathode is one of the main parts of any battery. It is the site of the chemical reaction that creates the flow of electricity that propels a vehicle.
The electric power sector accounts for about 30 percent of U.S. emissions of carbon dioxide.
Since the early days of aviation, when an AC-type generator became a primary source of electrical power for all aircraft systems, the demand for electrical power has steadily grown. Following rapid technology and scientific advancements in the aerospace industry, the complexity and criticality of all aircraft systems have increased to the point where multiple independent and isolated electrical power sources are required. In such an environment, with two or more variable-frequency AC-type generators that can be simultaneously activated to provide electrical power to the aircraft power distribution system, a safe power transfer process becomes a major priority. This means that any two independent aircraft AC power sources with different frequencies or phase angles cannot be connected simultaneously to a common power bus. For this purpose, a power transfer protocol has been developed to prevent any aircraft parallel power sourcing and to provide a reliable AC generator connection to
Novakovic, Neno
Airborne compression-ignition engine operations differ significantly from those in ground vehicles, both in mission requirements and in operating conditions. Unique challenges exist in the aviation space, and electrification technologies originally developed for ground applications may be leveraged to address these considerations. One such technology, electrically assisted turbochargers (EATs), have the potential to address the following: increase the maximum system power output, directly control intake manifold air pressure, and reignite the engine at altitude conditions in the event of an engine flame-out. Sea-level experiments were carried out on a two-liter, four-cylinder compression-ignition engine with a commercial-off-the-shelf EAT that replaced the original turbocharger. The objective of these experiments was to demonstrate the technology, assess the performance, and evaluate control methods at sea level prior to altitude experimentation. This work covers the baseline
Pope, AaronKim, KennethSchroen, ErikClerkin, PeterMusser, MarshallMattson, JonathanMeininger, RikGibson, JosephKang, Sang-GukKruger, KurtHepp, KyleKweon, Chol-Bum
Researchers have created electrostatic materials that function even with extremely weak ultrasound, heralding the era of permanent implantable electronic devices in biomedicine. Recent research explores implantable medical devices that operate wirelessly, yet finding a safe energy source and protective materials remains challenging. Presently, titanium (Ti) is used due to its biocompatibility and durability. However, radio waves cannot pass through this metal, necessitating a separate antenna for wireless power transmission. Consequently, this enlarges the device size, creating more discomfort for patients.
Storing energy is one of the key challenges for implementing sustainable but intermittent electricity sources like solar and wind. Engineers at Sandia National Laboratories are collaborating with New Mexico-based CSolPower LLC to develop a very affordable method of accomplishing that storage.
Electrification of road transport is a critical step towards establishment of a sustainable transport ecosystem. However, a major hindrance to electric mobility is the high cost and weight of the battery pack. Downsizing the battery pack will not only address these issues, but will also reduce embedded emissions due to battery manufacturing. One approach towards reducing battery pack size and still offering the user of electric vehicles similar mobility experiences as in case of conventional vehicles is to set up extensive network of charging or battery swapping stations. Another approach is to provide the vehicle with required energy while it is on the move. However, conventional systems such as overhead line or conducting rails have several disadvantages in the urban environment. One solution that has come up in this regard in recent times is the concept of Electric Roads System (ERS), which involves dynamic wireless power transfer (DWPT) to the vehicles from power transmitters
Sardar, ArghyaPrasad, Mukti
In a rush to move towards a sustainable future, the number of electric vehicles has risen significantly in recent years. With this, the need for power to charge those vehicles has also increased. In any electric vehicle fleet location, there could be many vehicles with different arrival and departure times and energy requirements, which might vary every day. Depending on the geographical location, the available solar energy might differ. The electricity costs might change on an hourly basis. This in total can affect the charging costs. In addition, a non-optimal sizing of the energy components could result in an under-sized system, where the energy demands are not met, or it could result in an over-sized system, where the owner must invest more than required. Based on all the information related to vehicle charging load, electricity charges, energy intensity profile of renewable energy generation like solar and wind, an optimal size of components, operational cost, and investment
Munirajappa, ChandrashekaraShrivastava, HimanshuPrasad P, Shilpa
While many consider electricity a basic human right, there are places where people have never had access to it. Among the United Nations’ Sustainable Development Goals is global access to affordable, reliable, and sustainable energy by 2030. Recently, the U.N. reported that progress in global electrification had slowed due to the challenge of reaching those hardest to reach.
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