Search NASA⌕ Search

SEARCH · Search NASA

Results for “WIRELESS CHARGING”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Electromagnetic Shielding Design for 200 kW Stationary Wireless Charging of Light-Duty EV

Wireless power transfer (WPT) is a developing technology with the advantage of convenience and flexible charging. SAE recommended practice J2954 defines typical size and geometry with aluminum or ferrite plate shielding to limit leakage electromagnetic (EM) fields for WPT with power levels lower than 22 kVA from the input side. However, as the WPT power goes up to 100- or 200-kW level, EM safety surrounding the WPT becomes a critical concern. To address this oncoming safety challenge, a novel ferrite shielding design is proposed in this paper. Different misalignment scenarios in accordance with definitions in SAE J2954 are also taken into consideration to ensure EM safety under various operation scenarios. Simulation results, which are preliminarily verified by magnetic field measurements at 1.1 m from the center of the vehicle side coil under 100 kW operation, indicate that the magnetic field leakage can be maintained below the limits defined in SAE J2954 for 200 kW operation. A 3.3 kW scale-down test was also carried out and compared to parallel scale-down simulations. 26.8% field emission reduction is observed from the scale-down test, which supports the effectiveness of the proposed shielding design.

25 ENERGY STORAGE↗
DOE OSTI2020

Electromagnetic Shielding Design for 200 kW Stationary Wireless Charging of Light-Duty EV

Wireless power transfer (WPT) is a developing technology with the advantage of convenience and flexible charging. SAE recommended practice J2954 defines typical size and geometry with aluminum or ferrite plate shielding to limit leakage electromagnetic (EM) fields for WPT with power levels lower than 22 kVA from the input side. However, as the WPT power goes up to 100- or 200-kW level, EM safety surrounding the WPT becomes a critical concern. To address this oncoming safety challenge, a novel ferrite shielding design is proposed in this paper. Different misalignment scenarios in accordance with definitions in SAE J2954 are also taken into consideration to ensure EM safety under various operation scenarios. Simulation results, which are preliminarily verified by magnetic field measurements at 1.1 m from the center of the vehicle side coil under 100 kW operation, indicate that the magnetic field leakage can be maintained below the limits defined in SAE J2954 for 200 kW operation. A 3.3 kW scale-down test was also carried out and compared to parallel scale-down simulations. 26.8% field emission reduction is observed from the scale-down test, which supports the effectiveness of the proposed shielding design.

Zhang, Bo↗
DOE OSTI2016

Wireless Charging for Electric Vehicles

Thanks to a project between the Energy Department, Oak Ridge National Laboratory and industry, electric vehicle drivers could soon be pulling the plug on their charging stations.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2019

A Coil Detection System for Dynamic Wireless Charging of Electric Vehicle

Application of wireless power transfer while EV is in motion can significantly reduce the battery storage capacity. A major challenge in implementation of dynamic wireless power transfer (DWPT) is automatic detection of EV to avoid loss in efficiency and alleviate any safety concerns. This paper proposes a novel coil detection method for segmented DWPT. Detection of the EV ahead of its arrival will initiate energizing of the transmitter buried inside the road to enable just-in-time transfer of power. At low speeds, communication can be a reliable method to power up the transmitter coil. However, at high speeds on highways, communication latency time for the detection of an EV is long and hence impractical. This paper proposes a low cost and low power EV detection system based on a novel orthogonal coil arrangement to detect EVs traveling at high speeds. Here, the proposed detection system was tested on a laboratory scale prototype for verification purpose. For high speed verification, simulation in PLECS was conducted to test the functionality of the proposed system.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2025

Field-Focused Load-Leveled Dynamic Wireless Charging System for Electric Vehicles

Electric vehicles offer much higher well-to-wheel efficiency than gasoline vehicles and can significantly reduce U.S. dependence on foreign oil, lower greenhouse gas emissions, improve local air quality, and support continued technological and economic growth. Despite these advantages, widespread adoption remains constrained by limitations in current battery technology, including high cost, limited driving range, and long charging times. One promising approach to address these challenges is to reduce onboard energy storage and instead deliver power wirelessly to vehicles while they are at a traffic stop or in motion.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2017

Robust planning of dynamic wireless charging infrastructure for battery electric buses

Battery electric buses with zero tailpipe emissions have great potential in improving environmental sustainability and livability of urban areas. However, the problems of high cost and limited range associated with on-board batteries have substantially limited the popularity of battery electric buses. The technology of dynamic wireless power transfer (DWPT), which provides bus operators with the ability to charge buses while in motion, may be able to effectively alleviate the drawbacks of electric buses. In this paper, we address the problem of simultaneously selecting the optimal location of the DWPT facilities and designing the optimal battery sizes of electric buses for a DWPT electric bus system. The problem is first constructed as a deterministic model in which the uncertainty of energy consumption and travel time of electric buses is neglected. The methodology of robust optimization (RO) is then adopted to address the uncertainty of energy consumption and travel time. The affinely adjustable robust counterpart (AARC) of the deterministic model is developed, and its equivalent tractable mathematical programming is derived. Both the deterministic model and the robust model are demonstrated with a real-world bus system. The results of our study demonstrate that the proposed deterministic model can effectively determine the allocation of DWPT facilities and the battery sizes of electric buses for a DWPT electric bus system; and the robust model can further provide optimal designs that are robust against the uncertainty of energy consumption and travel time for electric buses.

25 ENERGY STORAGE↗
DOE OSTI2017

High Efficiency, Low EMI and Positioning Tolerant Wireless Charging of EVs

The objective of this project is to develop, implement, and demonstrate a wireless power transfer (WPT) system that is capable of the following metrics: Total system efficiencies of more than 85 percent with minimum 20 cm coil-to-coil gap; System output power at least 6.6 kW; but design system up to 19.2 kW for future higher power study; Maximum lateral positioning tolerance achievable while meeting regulatory emission guidelines.

25 ENERGY STORAGE↗
DOE OSTI2016

Opportunistic Wireless Charging System Design for an On-Demand Shuttle Service

System right-sizing is critical to the implementation of in-motion wireless power transfer (WPT) for electric vehicles. This study evaluates potential system designs for an on-demand employee shuttle by determining the required battery size based on the rated power at a variable number of charging locations. Vehicle power and state of charge are simulated over the drive cycle, based on position and velocity data at every second from the existing shuttle. Adding just one WPT location can halve the battery size. Many configurations are capable of self-sustaining with WPT, while others benefit from supplemental stationary charging.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2018

Coil Power Density Optimization and Trade-off Study for a 100kW Electric Vehicle IPT Wireless Charging System

This paper presents a trade–off study examining the impacts of modifying resonant frequency and coil current density on coil power density for a 100kW electric vehicle charging system. We find that power density can be increased significantly by moving to higher operating frequency and current density with marginal impact to overall coil–to–coil transfer efficiency. A detailed prototype model of a 150 kVA rated coil set is presented along with loss estimates from magnetic field simulations and initial test results up to 50kW.

Pries, Jason↗
DOE OSTI2020

Copper-Clad Aluminum Windings as an Alternative Conductor for High-Power Electric Vehicle Wireless Charging

In this paper, copper and copper-clad aluminum winding conductors were compared. The effective resistances as functions of frequency for the cored coils were compared using the 3D finite element model frequency sweep analysis for low, medium, and high frequencies. To compare equivalent designs, both coils were designed to have similar direct-current resistance. Benefits of the copper-clad aluminum over the copper coils are presented.

Wojda, Rafal↗
DOE OSTI2019

Guest Editorial Special Issue on High-Power Fast Chargers and Wireless Charging

Electric transportation systems have made great strides forward in terms of performance and cost-effectiveness. Electric drivetrains provide better efficiency and higher reliability due to the lower complexity and smaller part numbers compared to combustion-based drivetrains. As such, electric transportation concepts are becoming viable for all modes of transportation. Here, this move toward transportation electrification is enabled by the drastic improvements in battery performance, making passenger vehicles with a range of over 200 mi cost-competitive with petroleum-powered vehicles. Despite the increasing number of electric vehicles (EVs) on the roads, the lack of charging infrastructure and long charging times restricts the use of these vehicles for daily commutes and short-distance trips.

33 ADVANCED PROPULSION SYSTEMS↗