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Results for “WIRELESS POWER”

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.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

Wireless Power Transfer for Space Applications

This paper introduces an implementation for magnetic resonance wireless power transfer for space applications. The analysis includes an equivalent impedance study, loop material characterization, source/load resonance coupling technique, and system response behavior due to loads variability. System characterization is accomplished by executing circuit design from analytical equations and simulations using Matlab and SPICE. The theory was validated by a combination of different experiments that includes loop material consideration, resonance coupling circuits considerations, electric loads considerations and a small scale proof-of-concept prototype. Experiment results shows successful wireless power transfer for all the cases studied. The prototype provided about 4.5 W of power to the load at a separation of -5 cm from the source using a power amplifier rated for 7 W.

Ramos, Gabriel Vazquez↗
DOE OSTI2020

A Novel AC to AC Wireless Power Transfer System for EV Charging Applications

In this paper, a novel ac to ac wireless power transfer (WPT) system is introduced for electric vehicle (EV) charging applications to reduce cost and design complexity. The presented wireless power transfer concept achieves unity power factor (UPF) on the grid-side by using a hybrid frequency ac / ac converter without an additional converter stage and closed loop control compared to the conventional systems. Due to inherent merit of the proposed ac / ac converter, ac input with 60 Hz grid frequency can be directly transferred to the load by superimposing with high frequency switching signal through the wireless coils. To validate the theoretical analysis of the proposed WPT system, the experimental results of the proposed converter are provided for 650 W output power by using 6 inches air gap between the couplers with the input of 110 VRMS ac source. The system overall efficiency is measured 89 % achieving 0.99 power factor (PF) and 1.5 % current total harmonic distortion (THD).

Asa, Erdem↗
DOE OSTI2023

Designing Dynamic Wireless Power Transfer Corridors for Heavy Duty Battery Electric Commercial Freight Vehicles

The use of wireless power transfer systems, consisting of inductive electrical coils on the vehicle and the power source may be designed for dynamic operations where the vehicle will absorb energy at highway speeds from transmitting coils in the road. This has the potential to reduce the onboard energy storage requirements for vehicles while enabling significantly longer missions. This paper presents an approach to architecting a dynamic wireless power transfer corridor for heavy duty battery electric commercial freight vehicles. By considering the interplay of roadway power capacity, roadway and vehicle coil coverage, seasonal road traffic loading, freight vehicle class and weight, vehicle mobility energy requirements, on-board battery chemistry, non-electrified roadway vehicle range requirements, grid capacity, substation locations, and variations in electricity costs, we minimize the vehicle TCO by architecting the electrified roadway and the vehicle battery simultaneously. The idea optimizes battery size and chemistry so that the depth of discharge between recharge events and expected life are balanced, thus fully utilizing the energy available throughout the course of the battery system's life. The approach is illustrated by applying it to the I-75 freight corridor, where the framework developed may be expanded and applied to a larger interstate system, expanded regional corridor, or other transportation network.

Sujan, Vivek↗
DOE OSTI2025

Circuit Modeling, Simulation, and Experimental Validation of a 100-kW Polyphase Wireless Power Transfer System for EV Applications

Polyphase wireless power transfer (WPT) systems can achieve much higher surface power densities (kW/m2) and specific power levels (kW/kg) compared to the conventional circular single phase WPT systems. Therefore, polyphase WPT systems can reduce the size, weight, volume, and cost of the WPT systems and can simplify the electric vehicle integration with less demand for space. This study presents the high-performance and compact 100-kW WPT development using polyphase electromagnetic coupling coils with rotating magnetic fields.

Onar, Omer [ORNL] (ORCID:0000000292028857)↗
DOE OSTI2019

Analysis of Dead-Time in a Single Phase Wireless Power Transfer System

In this paper, the effect of dead-time in a single phase wireless power transfer system (WPT) between the complementary switching pulses of the inverter leg is discussed in detail. The dead-time is always provided between the complementary switching pulses in the inverter leg to avoid the short-circuit of the input dc source. In WPT systems, high-frequency (HF) operation is desired to reduce the size of the passive components. As the frequency of operation increases, the dead-time effect becomes significant and must be addressed appropriately. This paper presents the analysis of the dead-time effect in the wireless power transfer system for an electric vehicle (EV) battery charging application. The operating waveforms for the given operating condition of the phase-shift angle and the power-factor are presented and the phenomenon of voltage polarity reversal (VPR) or notch is discussed. The effect of the notch on the fundamental component of the voltage is presented and the effect of the notch on the BMW i3 battery charging profile is evaluated. The theoretical analysis of the dead-time is verified using simulation results in PLECS.

Kavimandan, Utkarsh↗
DOE OSTI2016

A review of wireless power transfer for electric vehicles: Prospects to enhance sustainable mobility

Wireless power transfer (WPT), which transmits power by an electromagnetic field across an intervening space, provides the prospect of new opportunities for electric vehicles (EVs) to enhance sustainable mobility. In this review article we evaluate WPT technology for EV applications from both technical and sustainability perspectives. The objectives of this review include: (1) to present the state-of-the-art technical progress and research bottlenecks in WPT development and applications in the transportation sector; (2) to characterize the demonstrations of the real-world deployment of WPT EV systems; and (3) to evaluate the sustainable performance and identify challenges and opportunities for improvement. From the technical perspective, progress on coil design, compensation topologies, and power electronics converters and control methods are reviewed with a focus on system performance. From the sustainability perspective, performance is defined in terms of energy, environmental, and economic metrics, and policy drivers and issues of health and safety are also examined.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2020

20-kW Bi-directional Wireless Power Transfer System with Energy Storage System Connectivity

The severity of the economic impact caused by grid outages has been the driving factor for creating innovative solutions that increases interest for the deployment of distributed energy resources to reduce the impact of grid outages. This study presents a novel way of providing export power using bi-directional wireless power transfer (WPT) systems for ac grid side power and mobile energy storage systems (ESSs) connectivity. The proposed concept here interfaces the EV batteries to the AC grid and also can redirect the power from the stationary ESS to grid, to EV batteries, or both simultaneously; providing the capabilities of an uninterrupted power supply (UPS). Results demonstrate the performance and the functionality of the system with overall efficiencies 93% to 97%, depending on the operating mode.

Onar, Omer↗
DOE OSTI2019

Variable Duty Control of Three-Phase Voltage Source Inverter for Wireless Power Transfer Systems

This paper presents duty control and analysis of the three-phase voltage source inverter (VSI) to adjust the output power for three-phase wireless power transfer (WPT) applications. Analytical results show significant reductions in the inverter dc link ripple current with the three-phase system over single-phase WPT counterparts. Simulation and experimental results for an 18 kW three-phase series-series WPT system are included to validate the duty control and analysis. Experimental results also demonstrated the output voltage can be controlled over a wide range by adjusting the inverter duty.

Su, Gui-Jia↗
DOE OSTI2026

Development of Wireless Power Technology for Use in Electrochromic Window Retrofit Applications

Electrochromic (EC) windows, often referred to as smart windows, have the ability to adjust their tint in response to electrical signals, thereby controlling the amount of sunlight and heat entering a building. This dynamic modulation can lead to significant energy savings by reducing the reliance on artificial lighting and minimizing the load on heating, ventilation, and air conditioning (HVAC) systems. However, the widespread adoption of electrochromic window technology, especially in existing buildings, faces challenges, particularly concerning the installation cost associated with the need for electrical wiring to power and control the EC glass (tinting). In this project, GuRu Wireless demonstrated that it’s mmWave-based wireless power energy transfer technology can provide the necessary power for operation of electrochromic windows, wirelessly, and address the wiring challenges of electrochromic windows in retrofit applications.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2024

Design of High-Power Polyphase PCB Coil Systems for Wireless Power Transfer

Printed circuit board (PCB) coils have been proposed prior for implementation as inductive wireless charging coils to minimize size and cost. Utilization of PCBs can allow for a reduced cost, improved manufacturability, and a wide range of geometric customization options. To circumvent material limitations on insulation and thermal performance, parallel paths can be implemented to divide the current per path accordingly. Within this paper, an unconventional high-power PCB coil is designed employing all possible techniques for wiring with axial and radial parallel paths with equivalent transposition to minimize circulating currents. Design studies are simulated in 3D finite element analysis (FEA) to evaluate imbalance between phases with and without transposition. Two experimental prototype coils were fabricated with measurements for self-inductance and mutual inductance between phases. These measurements were validated to be sufficiently consistent with FEA results. Additionally, a method is proposed for a two-step optimization of coupling coefficient and coil losses.

Lewis, Donovin D.↗
DOE OSTI2024

Zero-power wireless system for crop water content monitoring

Zero power wireless sensors, devices, and systems are used for crop water content monitoring. The sensors consume no power while monitoring for the presence of dry crop conditions. Infrared reflectance from plants is measured and when selected spectral conditions are met, a circuit is closed, activating an alarm, an RFID tag, or a radio transmitter. The deployed sensors consume no power while monitoring, reducing or eliminating the need to change batteries.

Rinaldi, Matteo↗
NASA NTRSDate not supplied

Impedance Matching a Quarter Wave Resonant Receiver to Improve Efficiency in Unipolar Capacitive Wireless Power Transfer

Impedance matching techniques to achieve high performance in conventional wireless power transfer (WPT) systems are well established. These WPT systems are modelled as a lumped circuit, where the voltages/currents are approximately uniform and mostly unaffected by parasitic elements. However, a group of WPT techniques exist that utilize parasitic elements to form a highly resonant power transfer condition at high quality factors, exploiting a distributed circuit operation that can be modeled as a mutually coupled transmission line. A calculated matching network typically becomes unmatched when connected to the transmission line, as it changes the electrical structure of the coupled transmission line. This is particularly true for WPT systems that use quarter wave (QWR) or half wave resonators (HWR) for the receiver. Here we present one technique of matching to a mutually coupled transmission line where a parallel path is formed that improves the power transfer efficiency without severely altering the transmission line characteristics.

Wireless↗
DOE OSTI2015

Wireless power transfer test system

A testing system for wireless power transfer systems, including a stationary plate, a rotating plate, and a driver to rotate the rotating plate with respect to the stationary plate.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2021

Single-stage transmitter for wireless power transfer

A single-stage transmitter for wireless power transfer is provided. The transmitter includes a rectifier stage and an inverter stage sharing a first phase leg. The rectifier stage further includes a rectifying leg including two diodes connected in series, and a boost inductor coupling the first phase leg and the rectifying leg to an input port. The inverter stage further includes a second phase leg. Each phase leg includes two switches connected in series. The first and second phase legs are coupled to an output port. A bus capacitor is coupled across the first phase, second phase, and rectifying legs. A controller is programmed to determine first and second parameters, based on an output power at the output port, to simultaneously control the rectifier stage and the inverter stage to maintain constant bus voltage and achieve high power factor and low total harmonic distortion at the input port.

Costinett, Daniel Jes↗
DOE OSTI2018

Modeling, Simulation, and Experimental Verification of a 20-kW Series-Series Wireless Power Transfer System for a Toyota RAV4 Electric Vehicle

Wireless power transfer is going to play a major role in transportation electrification due the convenience, flexibility, safety, and high-efficiency. Achieving high power levels is important in order to reduce the charge times and provide more convenience to electric vehicle (EV) owners while keeping the efficiency high and electric and electromagnetic field emissions lower than the limits set by the international guidelines. This study presents a 20-kW wireless charging system designed for a Toyota RAV4 electric vehicle for stationary charging with a dc-to-dc (high-frequency inverter input to the vehicle battery terminals) efficiency exceeding 95% over four power conversion stages. Additionally, the modeling, analysis, and sensitivity of the wireless charging system are presented for series-series resonant tuning configuration.

Onar, Omer↗
DOE OSTI2020

A Control Scheme to Mitigate the Dead-Time Effects in a Wireless Power Transfer System

In practice, a dead-time is always provided between the complementary switching instances of the inverter phase-leg devices. At higher operating frequencies, the dead-time issues in wireless power transfer (WPT) systems become critical, especially as the power level increases. In certain operating conditions, the dead-time effect in wireless power transfer system affects the switching characteristics. Consequently, the switching losses in the power semiconductor devices increase and also impact the efficiency of the overall system. In this paper, a simple control scheme is proposed to eliminate the dead-time effect (or voltage polarity reversal) in the WPT inverter. The proposed control scheme monitors the inverter output voltage, and the switching frequency is auto-tuned to eliminate the undesired switching instances in the inverter voltage. The proposed control scheme is validated using the closed-loop simulations in PLECS, and the experimental results on a 5.6 kW WPT prototype are also presented. After eliminating the voltage-polarity-reversal at the inverter output, the inverter losses were reduced by ~40%, and the overall system losses were reduced by ~17%.

Kavimandan, Utkarsh↗
DOE OSTI2021

Miniature Coil for Wireless Power and Data Transfer through Aluminum

This paper presents the design and development of miniature coils for wireless power and data transfer through metal. Our coil has a total size of 15 mm × 13 mm × 6 mm. Experimental results demonstrate that we can harvest 440 mW through a 1 mm-thick aluminum plate. Aluminum and stainless-steel barriers of different thicknesses were used to characterize coil performance. Using a pair of the designed coils, we have developed a through-metal communication system to successfully transfer data through a 1 mm-thick aluminum plate. A maximum data rate of 100 bps was achieved using only harvested power. To the best of our knowledge, this is the first report that demonstrates power and data transfer through aluminum using miniature coils.

42 ENGINEERING↗
DOE OSTI2016

A High-Power Wireless Charging System Development and Integration for a Toyota RAV4 Electric Vehicle

Several wireless charging methods are underdevelopment or available as an aftermarket option in the light-duty automotive market. However, there are not many studies detailing the vehicle integrations, particularly a complete vehicle integration with higher power levels. This paper presents the development, implementation, and vehicle integration of a high-power (>10 kW) wireless power transfer (WPT)-based electric vehicle (EV) charging system for a Toyota RAV4 vehicle. The power stages of the system are introduced with the design specifications and control systems including the active front-end rectifier with power factor correction (PFC), high frequency power inverter, high frequency isolation transformer, coupling coils, vehicle side full-bridge rectifier and filter, and the vehicle battery. The operating principles of the control, communications, and protection systems are also presented in addition to the alignment and the driver interface system. The physical limitations of the system are also defined that would prevent the system operating at higher levels. The experiments are carried out using the integrated vehicle and the results obtained to demonstrate the system performance including the stage-by-stage efficiencies with matched and interoperable primary and secondary coils.

plug-in electric vehicle charger↗