Search NASA⌕ Search

SEARCH · Search NASA

Results for “Wireless”

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

Output Current Estimation and Control in Primary Side LCC Secondary Side Series Compensated Wireless Power Transfer System without Secondary Side Sensors

The estimation (and control) of the output variables is often challenging for wireless power transfer (WPT) systems. This paper presents a secondary side sensor-less closed loop estimation technique to estimate the output current in a primary side LCC and secondary side series compensated WPT system. Using information of primary side variables, the proposed estimation can estimate the output current over a wide range of load current variations. Results are presented to verify the efficacy of the proposed estimation.

Mukherjee, Subho [ORNL] (ORCID:0009000672297925)↗

Multi-phase Wireless Power Transfer with High Power Density Inductive Coils for Electric Drone Charging

Wireless charging of unmanned ground vehi-cles and aircraft has been proposed to increase charging reliability and security, allow for autonomous functionality, and either reduce battery size or increase continuous flight time. This paper proposes a three-phase Litz wire primary and a two-phase PCB secondary for high secondary-side power density considering misalignment tolerances, surface and volumetric power density, and coil sizing. Elec-tromagnetic 3D finite element analysis (FEA) simulations are conducted to study variation in mutual inductance and coupling coefficient with different secondary coil sizes and number of turns, horizontal and vertical misalignment between the primary and secondary, and a combination of both for a set of designs with the same rated power. Results indicate that receiver coils of reduced size relative to the primary can deliver rated power for increased power density and higher tolerance to misalignment.

Gastineau, Lucas [University of Kentucky]↗

Intercell Power Transformer for Power Balancing of Polyphase Wireless Power Transfer Systems

Polyphase wireless power transfer (PWPT) systems experience receiver side imbalances in misaligned conditions. This paper proposes a method for power balancing in PWPT systems, specifically addressing the challenges caused by receivers coil unequal coupling. An intercell power transformer (IPT) is introduced at the receiver side to mitigate the effects of coil mismatch. Simulations of the PWPT system incorporating IPT demonstrate its effectiveness in enhancing power distribution. For voltage-fed rectifiers (VFR), the IPT increases the conduction angle, resulting in higher output power. In current- fed rectifiers (CFR), the IPT promotes uniform power sharing among rectifiers, thereby reducing electrical stress on semiconductor devices and passive components. Simulation results indicate that, under coil misalignment, the IPT improves output power by approximately 49% for VFRs and 44% for CFRs compared to conventional PWPT systems without IPT.

Wojda, Rafal [ORNL] (ORCID:0000000286609268)↗

Three and Two Phase Rotating Field Inductive Couplers for Wireless Power Transfer with One Phase per Layer Windings

Multiphase inductive wireless charging coils have been proposed recently to improve coupler surface power density, reduce component stress and size, and provide near-constant power delivery to charge mobile electric systems. Several aspects for the fundamental characterization of multiphase coils are explored up to six phases including approximate mutual inductance with size and turn variation, induced voltage, and output power estimation. The relative component stress and size of passive components for resonant operation are compared between the multiphase variants. A combination of an experimentally validated 3D electromagnetic finite element analysis (FEA) and power electronic co-simulations are used to validate the estimated quantities approximated with a mixture of analytical equations and an artificial neural network model for mutual inductance. A novel three-phase transmitter, two-phase receiver coil pair is also proposed for electric vehicle charging to reduce the number of connections and compensation complexity on the vehicle-side with improved power output compared to a two-phase configuration.

Lewis, Donovin D. [University of Kentucky]↗

A Unified Wireless Charger, On-Board Charger, and Auxiliary Power Module for Electric Vehicle Charging Systems

This paper proposes a unified electric vehicle (EV) charging architecture that integrates wireless power transfer (WPT), an on-board charger (OBC), and an auxiliary power module (APM) within a single architecture. By sharing a multi-functional magnetic structure and active switch bridges, the proposed topology eliminates additional transformers and converter stages, reducing hardware complexity and improving power density. A multipurpose magnetic design achieves magnetic decoupling among the WPT, OBC, and APM functions while maintaining the required coupling for each mode. Through electrical reconfiguration, the WPT operates as an LCC-S converter, whereas the OBC and APM operate as dual-active-bridge (DAB) converters. The system supports multiple operating modes, including simultaneous high-voltage and lowvoltage battery charging. Finite-element and circuit simulations verify the magnetic characteristics and system operation, demonstrating the feasibility of the proposed unified architecture for EV charging applications.

Jo, Cheolhui [ORNL] (ORCID:0000000322692434)↗

Design and Performance Assessment of Intermediary Coils for Misalignment Tolerance Improvement in Wireless Power Transfer Systems

This paper investigates the use of intermediate coils positioned between the primary and secondary coils in Wireless Power Transfer (WPT) systems for electric vehicle (EV) charging, with the objective of improving power transfer efficiency and robustness under misalignment conditions. An optimized 1 kW power system that operates at 85 kHz is developed and the misalignment performance was analyzed and compared with and without intermediate coils. A preliminary increase in efficiency of 2.3% at a misalignment of 52% of the coil radius is shown to be possible for a passive intermediate coil. An experimental prototype is built for design verification.

Sivka, Gozde [ORNL]↗

A Perspective on the Impact of Group Delay Dispersion in Future Terahertz Wireless Systems

This article discusses the challenges and opportunities of managing group delay dispersion (GDD), and its relation to the performance standards of future sixth-generation (6G) wireless communication systems utilizing terahertz frequency waves. The unique susceptibilities of 6G systems to GDD are described, along with a quantitative description of the sources of GDD, including multipath, rough surface scattering, intelligent reflecting surfaces, and propagation through the atmosphere. An experimental case-study is presented that confirms previous models quantifying the impact of atmospheric GDD. Several GDD manipulation strategies are presented, illustrating their hindered effectiveness in the 6G context. Conversely, some benefits of leveraging GDD to enhance 6G systems, such as improved security and simplified hardware, are also discussed. Finally, a perspective on using photonic GDD control devices is provided, revealing quantitative benefits that may unburden existing equalization schemes. Here, the article argues that GDD will uniquely and significantly impact some 6G systems, but that its careful consideration along with new mitigation strategies, including photonic devices, will help optimize system performance. The conclusion provides a perspective to guide future research in this area.

Strecker, Karl↗

COSMIC DAWN: Distributed Analysis of Wireless at Nextscale

Distributed Analysis of Wireless at Nextscale (DAWN) is a novel simulation framework for large-scale design-space exploration (DSE) of unmodified software-defined radio (SDR) applications interacting in a scalable, high-fidelity, virtual physics environment. The software-defined nature of the coupled software-physics simulation leverages hardware emulation to permit in-depth examination and modification of not only the electromagnetic environment, including each signal in flight, but also the precise state of system software and components. DAWN supports modular, customizable physics environments allowing realistic propagation effects so that computationally efficient empirical models, reduced order/surrogate models, or large-scale, high-fidelity, site-specific simulations can be used as a propagation medium based on scenario requirements. This paper introduces DAWN’s design and initial implementation, detailing key architectural components, including the Physics Realization Engine (PhyRE), Runtime Infrastructure for Simulation Environments (RISE), and the design space exploration (DSE) suite. It concludes with demonstrations using unmodified 4G/LTE software available from srsRAN on computing resources ranging from a small cluster to ORNL’s Frontier Exascale system.

Wise, Mike [ORNL] (ORCID:0000000266120641)↗

Wireless power transfer apparatus with radially arrayed magnetic structures

An apparatus includes a first coil, a second coil having a first side facing a first side of the first coil, a first radial array of magnetic material bodies disposed on a second side of the first coil, and a second radial array of magnetic material bodies disposed on a second side of the second coil such that respective magnetic material bodies of the second radial array overlap respective magnetic material bodies of the first radial array. The apparatus may be included in a wireless power transfer system.

Pahl, Birger↗

How efficiently can AI recognize Wireless Devices?

This poster presents a hardware benchmarking methodology for a 3-layer CNN waveform classifier deployed using ONNX Runtime on an NVIDIA Jetson AGX Orin. The dataset consist of 9 signal types, -30 to +30 dB SNR with 5dB increments. Benchmarking on the Jetson AGX Orin gave an accuracy of 91.9% and GPU throughput of 107,120 predictions/sec (23× faster than CPU). The Jetson GPU reached approximately 27M samples/sec with stable performance but fell below the 40 MHz rate needed for real-time radio feeds. Sustained testing of 5 minutes confirmed stable performance with no memory leaks, establishing a reproducible benchmarking baseline for future edge-deployment optimization.

99 - GENERAL AND MISCELLANEOUS↗