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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 1,657 records · Page 92
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Triaxial photoconductive switch module

Methods, systems, and devices describe triaxial photoconductive switch modules that include a center conductor, an inner conductor, an outer conductor, a high voltage capacitor that is formed between the center conductor and the inner conductor, and a photoconductive switch that is formed between the center conductor and a section of the outer conductor. The disclosed triaxial photoconductive switch modules include low inductance current paths that lead to high current efficiencies. Furthermore, the disclosed triaxial photoconductive switch modules eliminate or reduce parasitic capacitance problems of existing systems.

Nelson, Scott D.↗
DOE OSTI2019

Systems and methods for synchronizing converter modules

Various examples are directed to a converter system comprising first and second series-connected converter modules and a synchronization circuit. The synchronization circuit may modulate a reference signal onto a carrier signal to generate a synchronization current signal and the synchronization current signal to an output current of the converter system to generate an aggregated output current. A first converter module may receive the aggregated output current from a first current sensor and generate a first reproduced synchronization signal at least in part from the aggregated output current. A first switch control signal for switching at least one switch at the first converter may be generated based at least in part on the first reproduced synchronization signal.

Cox, Robert Williams↗
DOE OSTI2020

High Efficiency Silicon Module Degradation - From Atoms to Systems: Preprint

For PV to be cost competitive with traditional energy sources reliability is of critical importance. Historically, PV reliability has focused on the module packaging because degradation and failure modes were directly linked to the packaging. Today, in addition to module packaging cell related reliability issues can be observed. We show that silicon heterojunction (SHJ) degradation is directly linked to the re-distribution of hydrogen (H) near the interface between the amorphous-silicon (a-Si) and silicon bulk. PERC modules show a similar decline in carrier lifetime indicating that not the packaging but the cells are also changing during field exposure. Examination of a stressed PERC cell showed a similar H redistribution in the cell. Understanding the degradation mechanism at the atomic level is important in facilitating possible mitigating mechanisms and more accurately projecting performance.

degradation↗
DOE OSTI2020

Liquid-Cooled Heat Sink Optimization for Thermal Imbalance Mitigation in Wide-Bandgap Power Modules

Power semiconductor die layout in substrates used in power modules is generally optimized for minimum electrical parasitics (e.g., stray inductance) by considering the minimum spacing between dies for thermal decoupling. The layout assumes sufficient heat spreading and transfer from dies to the cooling structure. For module designs using a direct substrate cooling method, the base plate is removed, leading to a steady-state thermal asymmetry in the power module due to insufficient heat spreading/transfer. This causes significant temperature differences among the devices. Such unintentional thermal asymmetries can lead to undesirable asymmetries in power conversion among semiconductor devices, which impact reliability. This article proposes a thermal imbalance mitigation method that uses evolutionary optimized liquid-cooled heat sinks to improve the thermal loading among devices.

Sahu, Raj↗
DOE OSTI2021

Employing Fracture Statistics to Track Cell Reliability Through Module Fabrication

In this work we demonstrate how fracture statistics may be employed to track cell reliability through module fabrication steps. We were able to detect how cell cutting equipment could reduce cell fracture strain by 25 % as well as increase its variability. A smaller reduction was found to result from the ribbon soldering operation, and all cells measured were weaker when strained in an orientation perpendicular to the gridlines. Cell fracture measurements were found to be consistent with the number of cracked cells experienced in full sized modules exposed to mechanical loading. A structural mechanics model was created to elucidate how the requisite fracture strain is developed in a cell encapsulated within a PV module and demonstrates that this strain decreases more than 50 % from its center to edge when placed within the inner loading span of four-point flexure. The associated implications on the apparent cell strength is examined with an effective volume treatment.

14 SOLAR ENERGY↗
DOE OSTI2021

Measurement techniques of thermoelectric devices and modules

Thermoelectric (TE) energy conversion devices are designed based on measured material transport properties. Although an ideal device efficiency can be calculated using the figure of merit, zT, the actual efficiency of a thermoelectric module is smaller and must be measured. TE device performance testing techniques and procedures are reviewed with a focus on energy conversion efficiency. One of the areas that attract less attention in the literature is the transition from basic thermoelectric materials research to the production of modules and devices. The effects of interface layers, diffusion barriers, thermal insulations, and heat sinks are reviewed. Finally, device performance from single couples to standard modules and long-term reliability are discussed.

Wang, Hsin↗
DOE OSTI2021

Electroabsorption optical modulator

An electroabsorption modulator that operates based on electroabsorption of a surface plasmon polariton mode is improved by various structural changes and/or selection of different materials. For example, at least a portion of the waveguide may be made to be conductive, e.g., by doping. Also, layers that make up the modulator structure may be placed along sides of waveguides in addition to or instead of simply on the top thereof. High permittivity gate dielectric materials may be employed. Also, materials other than ITO may be employed as a transparent conductor. Such an improved plasmonic electroabsorption modulator can be fabricated using standard semiconductor processing techniques and may be integrated with standard photonic integrated circuits, including silicon photonics and compound semiconductor-based platforms. Advantageously, high-speed, low-voltage operation over a wide spectrum of wavelengths may be achieved.

Wood, Michael↗
DOE OSTI2021

Methods of epsilon-near-zero optical modulation

A method of optical modulation in a non-resonant epsilon-near-zero (EMZ) plasmonic electro-optical modulator is provided. An optical carrier is injected into a waveguide optically coupled to a layer of transparent conductive material having an epsilon-near-zero (ENZ) wavelength. The transparent conductive material layer constitutes a portion of a capacitive structure that includes a gate dielectric layer. A time-varying bias voltage applied across the gate dielectric layer shifts the ENZ wavelength toward the carrier wavelength, and thereby impresses a phase modulation pattern on the carrier wave.

Wood, Michael↗
DOE OSTI2021

Power inverter module with reduced inductance

A power inverter module includes a base module having a plurality of electrically conductive layers, including a first conductive layer, a second conductive layer and a third conductive layer. A first terminal is operatively connected to the first conductive layer at a first end and a second terminal is operatively connected to the second conductive layer at the first end. An isolation sheet is sandwiched between the first and second terminals. The first terminal and the second terminal include a respective proximal portion composed of a first material and a respective distal portion composed of a second material. At least one of the first terminal and the second terminal is bent to create an overlap zone such that a gap between the first terminal and the second terminal in the overlap zone is less than a threshold distance. The power inverter module is configured to reduce parasitic inductance.

Jaksic, Marko↗
DOE OSTI2021

Hybrid chip-on-board LED module with patterned encapsulation

Light modules and methods of forming light modules are disclosed. A light module includes a first plurality and a second plurality of light emitting elements configured to emit, respectively, a first light and a second light, and both arranged on a substrate. An encapsulation layer is disposed over the first and second plurality of the light emitting elements, and a wavelength converting element is dispersed in the encapsulation layer. A concentration of the wavelength converting element in the encapsulation layer varies, is larger over the first plurality of light emitting elements and is smaller over the second plurality of light emitting elements.

Soer, Wouter Anthon↗
DOE OSTI2014

Studies on the Module Structure for the NOvA Liquid Scintillator Neutrino Detector

This thesis contains studies pertinent to the construction of modules for the NOνAexperiment detectors. The tensile strength of acrylic and epoxy adhesives used in construction of the detector was studied over time and with various surface preparations. Sanding and corona discharge surface treatments increased the bond strength of the acrylic by 10-20%; aging in oil did not affect the acrylic bond strength while aging in air at 50°C for 9 months (equivalent to approximately 5 years at room temperature) increased the acrylic bond strength by 25%. For the epoxy, corona discharge treated samples’ strength increased slightly after aging while the strength of sanded samples in air remained consistent and sanded samples in oil decreased by 17% when aged at 50°C for 1.5 years (equivalent to approximately 10 years at room temperature).All materials used in the detector were studied to determine if degrading interaction would occur with the pseudocumene liquid scintillator. Substances such as acrylic adhesive and PTFE paste were found to interact with the scintillator while materials such as a variety of PVCs, epoxy adhesives, and PTFE tape were found to be non-reactive with the scintillator. Following the appearance of cracks on manifold covers in installed modules, studies were carried out to help to determine the cause and mitigation of these cracks. Manifold covers that had been pressure tested at various pressures during the check of the seals during the manufacturing process were examined for the formation of cracks. “Containment units” were used to constrain the swelling of the manifold covers during pressure testing. Internal cracks were visible on the majority of manifold covers tested at 1.4 bar with the original containment units. It was found that reducing the pressure testing of the modules from 1.4 bar to 0.7 bar and increasing the rigidity of the pressure test containment units eliminated the formation of visible cracks in the manifold covers. Stress concentration in small fillet radius injection molded PVC was studied. GeonM3500 PVC has a yield strength 12% greater than Geon M3800 PVC originally used for the manifold covers but increased the stress concentrated failure time by 6600% and was thus chosen to mold new manifold covers after a redesign to eliminate stress concentrating features.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Module-OT: A Turnkey Solution for Securing Energy Systems

The Modular Security Apparatus for Managing Distributed Cryptography for Command-and-Control Messages on Operational Technology Networks (Module-OT) is a flexible and lightweight solution for grid-edge devices focusing on end-to-end security. It is a bump- in- the-wire solution acting as a secure conduit for data between devices or systems across a network. It improves the cybersecurity posture of DER systems by providing authentication, authorization, and data integrity to secure DER communications. Additionally, it performs key management, provides data security through whitelisting Internet Protocol addresses and ports, blocks unauthorized connections, controls user access, and allows serial or Ethernet connections for added flexibility. The core software is portable to various Linux-based operating systems and is developed to be customized by the developer and researcher communities. Module-OT has been validated in the lab, has been demonstrated at a 500-KW PV-plus-storage site, and has been proven ready to secure operational technology devices. Its core functionality meets current standards, including validation procedures of the NIST Cryptographic Algorithm Validation Program (CAVP) and the Federal Information Processing Standard (FIPS 140-2). Because of its capability to provide an accessible and affordable option for stepping up security across modern energy systems, Module-OT can serve as an effective technological option to standardize cybersecurity moving forward.

cryptography↗
DOE OSTI2022

Techniques for charging and/or discharging a battery using frequency modulation

Described herein are techniques that increase the charging and/or discharging rate of a rechargeable battery, at least in part, by using frequency modulated (FM) signals having a frequency in the megahertz (MHz) frequency range. In some embodiments, the MHz frequency range may include any frequency between 0.1 MHz and 1 gigahertz (GHz). In some embodiments, a battery charger described herein may be configured to generate and transmit, to a battery, an FM signal modulated over a frequency range during a period of time, the FM signal having a frequency of at least 0.5 MHz during at least a first portion of the period of time. In some embodiments, a method described herein includes transmitting an FM signal modulated over a frequency range during a period of time and having a frequency of at least 0.5 MHz during at least a first portion of the period of time to a battery.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2023

GBT20, a 20.48 Gbps PAM4 Optical Transmitter Module for Particle Physics Experiments

We present a pluggable radiation-tolerant 4-level Pulse-Amplitude-Modulation (PAM4) optical transmitter module called GBT20 (Giga-Bit Transmitter at 20 Gbps) for particle-physics experiments. GBT20 has an OSFP or firefly connector to input 16-bit data each at 1.28 Gbps. The GBT20 drives a VCSEL die with an LC lens or a VCSEL TOSA and interfaces an optical fiber with a standard LC connector. The minimum module, including the host connector, occupies 41 mm x 13 mm x 6 mm. At 20.48 Gbps, the minimum Transmitter Dispersion Eye Closure Quaternary (TDECQ) is around 0.7 dB. The power consumption is around 164 mW in the low-power mode. The SEE cross-section is below 7.5x10^(-14) cm^2. No significant performance degrades after a TID of 5.4 kGy.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

PERFORMANCE CHARACTERIZATION OF THE DIRECT CONTACT MEMBRANE DISTILLATION MODULE OPERATED WITH HIGHLY CONCENTRATED SOLUTION

The experimental study was conducted to characterize the performance of the flat sheet Direct Contact Membrane Distillation. The length degradation was studied in a short and long module with and without spacers. The experimental study is validated using the predicted flux for a wide range of operating conditions using deionized water. Three different membranes are used in the parametric study for feed Reynolds number varied between 500 and 2000, and inlet feed temperature varied between 45°C and 80°C. PTFE membrane was shown to be more effective than the PVDF due to its higher permeability coefficient and higher hydrophobicity. Fouling study was conducted on the selected PTFE membrane with various feed Reynolds numbers between 500 and 2000 and feed inlet temperature between 50°C and 80°C. Membranes used in the fouling study were characterized using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) for the morphology and chemical composition of the fouling layer. 36 hours of operation with 10 wt% NaCl (100,000 ppm) at feed inlet temperatures 80°C and 60°C and fixed Reynolds 2000 demonstrated a drop in flux by 31% and 27%, respectively. Low flow rate and high temperature are favorable conditions for fouling formation and reduced permeate flux for highly concentrated solutions. The spacers improved the flux by 30.8% and 27.6% at the operating Reynolds numbers 2000 the short and long channel modules. This study helps to design and optimize DCMD modules for industrial-size desalination and water treatment applications.

Kim, Deliya↗
DOE OSTI2022

The HUNTER Dynamic Human Reliability Analysis Tool: Development of a Module for Performance Shaping Factors

Human Unimodel for Nuclear Technology to Enhance Reliability (HUNTER) is a framework to support dynamic human reliability analysis (HRA) in communication with a variety of methods and tools. In this paper, how we have developed one of the HUNTER modules, the individual module for evaluating performance shaping factors (PSFs), is introduced. The PSF refers to any factor that influences human performance such as workload or complexity. It has been used for highlighting human errors and adjusting the error probabilities in the existing HRA. We consider the eight PSFs suggested in the Standardized Plant Analysis Risk-HRA (SPAR-H) method, which is the representative HRA method widely used in the nuclear field. To support our dynamic modeling using the eight SPAR-H PSFs, we reviewed human performance literature and developed data-based mathematical models to rate and quantify PSFs in the context of dynamic HRA. We also design the individual module composed of the two functions: 1) the PSF qualification function that automatically or manually evaluates a PSF level, and 2) the PSF quantification function that dynamically or statically determines the PSF multiplier values and integrate them to adjust human error probabilities (HEPs). How each function works with the SPAR-H PSFs and how the PSFs adjust the HEPs are investigated through literature and discussed in this paper.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2023

Industry Facing PV Degradation Prediction Tool and Database to Enable a 50-Year Life Module

The Photovoltaic (PV) industry constantly aims for lower costs, higher-efficiency cells, and improved module designs. These trends lead to using new materials, designs, and manufacturing processes, resulting in a continually changing technological landscape. These changes can potentially introduce new, unknown degradation mechanisms and failure modes that are difficult to diagnose, analyze, test, and model. This introduces uncertainty into the expected lifetime of PV modules of 25 years. Furthermore, research efforts aim for up to 50 years of service life while keeping performance degradation at a minimum for decades of outdoor weathering - putting additional pressure on improving the accuracy of long-term durability and reliability assessments. Here there is a need to organize the existing degradation data into an accessible format and to provide industry relevant tools for extrapolation from laboratory to field conditions. Because the core of this type of analysis involves calculations that are complicated but ubiquitous for many degradation processes, an enhanced predictive modeling framework will facilitate the analysis to help researchers keep up with the rapid pace of technological changes. In this work, we present an online tool that can be used to search for and analyze degradation information and extrapolate PV module performance and durability to field exposure. A graphical user interface will aid in the understanding of the results. The prediction tool will be built modular and published as open source, enabling users to expand on the existing framework. We use an integration pipeline approach that allows us to leverage weather data from the National Solar Radiation Database to perform geospatial degradation analysis in the US and worldwide. Our repository will contain various degradation models and material parameters suitable for the reliability and durability assessment of materials and components deployed outdoors. We hope to become a repository that can be used for weathering and degradation analysis for various applications beyond the PV industry.

degradation↗
DOE OSTI2011

The Global Trigger Processor: A VXS Switch Module for Triggering Large Scale Data Acquisition Systems

The 12 GeV upgrade for Jefferson Lab's Continuous Electron Beam Accelerator Facility requires the development of a new data acquisition system to accommodate the proposed 200 kHz Level 1 trigger rates expected for fixed target experiments at 12 GeV. As part of a suite of trigger electronics comprised of VXS switch and payload modules, the Global Trigger Processor (GTP) will handle up to 32,768 channels of preprocessed trigger information data from the multiple detector systems that surround the beam target at a system clock rate of 250 MHz. The GTP is configured with user programmable Physics trigger equations and when trigger conditions are satisfied, the GTP will activate the storage of data for subsequent analysis. The GTP features an Altera Stratix IV GX FPGA allowing interface to 16 Sub-System Processor modules via 32 5-Gbps links, DDR2 and flash memory devices, two gigabit Ethernet interfaces using Nios II embedded processors, fiber optic transceivers, and trigger output signals. The GTP's high-bandwidth interconnect with the payload modules in the VXS crate, the Ethernet interface for parameter control, status monitoring, and remote update, and the inherent nature of its FPGA give it the flexibility to be used large variety of tasks and adapt to future needs. This paper details the responsibilities of the GTP, the hardware's role in meeting those requirements, and elements of the VXS architecture that facilitated the design of the trigger system. Also presented will be the current status of development including significant milestones and challenges.

Kaneta, Scott↗