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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 1,063 records · Page 59
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Comparison between 1.7 kV SiC SJT and MOSFET Power Modules

Abstract— In this paper, a comprehensive evaluation work on 1.7 kV SiC Super Junction Transistor (SJT) power module and 1.7 kV SiC MOSFET power modules is presented. Both device static and dynamic performance is extracted and compared at wide device current range and temperature range. The data presented in this paper can be used as input for medium voltage power conversion system power transistor selection, gate drive design and system level thermal management design. Since the SiC SJT is a new power transistor with unique current driven mechanism. A dedicated section discusses the SiC SJT power module gate drive configuration and device false turn on suppress as well. In a summary, 1.7 kV SiC SJT shows superior on state conductivity, but similar switching performance compared to 1.7 kV SiC MOSFET power modules.

gate drive↗
DOE OSTI2020

Passive bias temperature compensation circuit module

A passive bias temperature compensation module for silicon photomultiplier, avalanche photodiodes and similar photodetectors that possess a moderately linear temperature coefficient of gain and that may be compensated by varying an applied bias voltage. The module includes an electrical circuit and a method for determining component values to provide a constant voltage source to stabilize the gain of one or more photodetector devices. A temperature sensor in the module is held in close thermal contact with the photodetector and a filter capacitor is electrically close to the photodetector. The module is based on the concept of temperature sensitive voltage division which is applicable to situations in which large numbers of photodetectors must be gain-compensated for temperature variations over a wide range while maintaining excellent gain matching. The passive bias temperature compensation method enables multiple photodetectors to share a single constant voltage supply without loss of matching performance.

42 ENGINEERING↗
DOE OSTI2020

Constraining the Charge-Sign and Rigidity-Dependence of Solar Modulation

Our ability to identify the sources of cosmic rays and understand how these particles propagate through the interstellar medium is hindered by the combined effects of the solar wind and its embedded magnetic field, collectively known as solar modulation. In this paper, we build upon our previous work to model and constrain the effects of solar modulation on the cosmic-ray spectrum, using data from AMS-02 and BESS Polar II collected between 2007 and 2012, during which the heliospheric magnetic field was in a state of negative polarity. Our model uses measurements of the heliospheric magnetic field and the tilt angle of the heliospheric current sheet to accurately predict the effects of solar modulation as a function of time, charge, and rigidity. By incorporating data from a period of negative polarity, we have been able to robustly observe and constrain the charge-dependent effects of solar modulation.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Method and apparatus of surface-incident, plasmon-enhanced multiple quantum well modulators and optical coupling thereon

An optical interconnect system has first and second waveguides each with wedge-shaped cross-section at a first end, disposed over an optical modulator. The optical modulator is a surface-plasmon multi quantum well (SP-MQW) modulator, the first waveguide an input waveguide and the second waveguide configured an output waveguide. In embodiments the SP-MQW modulator has multiple semiconductor layers disposed atop a lower metal layer between 10 and 300 nanometers thick and configured such that incident light is reflected at the lower metal layer unless a voltage is applied to the semiconductor layers, when incident light is coupled into a surface plasmon mode in the lower metal layer.

42 ENGINEERING↗
DOE OSTI2020

Field Reliability of Glass/Glass Modules

A review of literature indicates that there will be a 20% increase in utilization of glass/glass PV modules by 2023. Common degradation modes reported in literature of glass/glass modules are: Encapsulant delamination, Encapsulant browning, corrosion and glass cracks. There is a strong need to investigate the reliability of glass/glass modules in detail to identify and overcome any potential failures in the future constructions. This work presents a preliminary literature review on the reliability of old generation glass/glass modules in the field.

14 SOLAR ENERGY↗
DOE OSTI2021

Systems and methods for reworking shingled solar cell modules

A high efficiency configuration for a solar cell module comprises solar cells arranged in a shingled manner to form super cells, which may be arranged to efficiently use the area of the solar module, reduce series resistance, and increase module efficiency. Removing a defective solar cell from a super cell may be difficult, however. It may therefore be advantageous to bypass defective solar cells in a super cell rather than remove and replace them. A bypass conductor may be applied to the rear surface of the super cell to bypass one or more defective solar cells in a super cell or in a solar module comprising super cells.

Caswell, Nathaniel Alexis↗
DOE OSTI2021

Integration of microinverter with photovoltaic module

Various technologies for integrating a microinverter with a photovoltaic module are disclosed. An alternating current photovoltaic (ACPV) module includes a photovoltaic module having a frame and a junction box including a direct current (DC) output connector, and a microinverter having a housing coupled to the frame and a DC input connector electrically mated with the DC output connector of the photovoltaic module.

Gilchrist, Phil↗
DOE OSTI2023

Scintillation light detection performance for the DUNE ND-LAr 2 × 2 modules

The Deep Underground Neutrino Experiment (DUNE) will be using a liquid argon time projection chamber (LAr TPC) with optically separated modules in the Near Detector (ND) complex. A prototype experiment, DUNE ND-LAr 2 × 2, is composed of four test modules. They detect ionization charge through a pixel-based readout and scintillation light through fibers in light collection modules and light traps called ArCLights. The light detection performance for two modules of DUNE ND-LAr 2 × 2 that took cosmic ray data at the University of Bern is shown. We present further the role of the 2 × 2 prototype in DUNE and how it is used to demonstrate the reconstruction capabilities of its light detectors in terms of energy thresholds and timing resolution.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2023

Rear-Side Irradiance Simulation of Field PV Modules: Preprint

Assessing the durability of photovoltaic (PV) module backsheet is critical to increasing module lifetime. Historically, laboratory-based accelerated testing has insufficient in predicting large-scale failures of commercial polymeric materials. Additionally, there is growing concern that standard condition tests do not reflect non-uniformities in field exposure, and that certain modules experience more severe degradation due to their location. Anisotropy in field exposures is installation dependent and reflects different levels of exposure to irradiance due to mounting geometry, ground surface albedo, and climatic zone. "Bificial Radiance" [1], simulates the amount of reflected irradiance on the Polyethylene Naphthalate (PEN) backsheet of a PV array located in Maryland. In our work, site specific weather data are gathered for the entire length of exposure for the modules. The total full-spectrum dose for the incident irradiance on the backsheet was then determined. The simulation results are integrated with historical field survey data to better understand realworld outdoor degradation.

backsheet↗
DOE OSTI2023

Stabilizers for a vehicle cooling module

A stabilizing arrangement of a cooling system module of a vehicle includes stabilizer pins attached to the vehicle cooling system module. Stabilizer slots are incorporated into a component of the chassis of the vehicle, such as a frame extender. The stabilizer slots may be formed as an upwards opening U-shape. Bushings are attached to the stabilizer pins. The stabilizer pins and bushings extend laterally into and engage with the stabilizer slots. Upon installation, the stabilizer pins and bushings are aligned with the stabilizer slots as the cooling system module is lowered onto the ISO mounts. The stabilizer pins and bushings slide vertically downwards into the stabilizer slots as the cooling system module is lowered into place. The simpler stabilizer pins, bushings, and stabilizer slots thereby take the place of expensive, time consuming, complex, labor intensive, and space consuming stay rod arrangements.

Wu, Shouhao↗
DOE OSTI2023

Resonant-based photonic intensity modulators integrated with fully etched thin-film lithium niobate waveguides

An apparatus such as an optical modulator includes a buried oxide layer is disposed on a substrate. A microring resonator and an optical waveguide are disposed on the buried oxide layer and within a bonded semiconductor layer. The optical waveguide is optically coupled to the microring resonator and inputs a first optical wave into the microring resonator. An oxide layer is deposited on top of the optical waveguide and the microring resonator. A set of electrodes is disposed adjacent to the microring resonator, and in response to an electrical signal, the set of electrodes modulates the first optical wave into a modulated optical wave of transverse magnetic polarization within the microring resonator and outputs the modulated optical wave to the optical waveguide.

Source record↗
DOE OSTI2023

Latest developments in the MOOSE fluid properties module

The fluid properties module in MOOSE serves a variety of fluid simulation applications based on MOOSE, including the MOOSE Navier Stokes module~\cite{moose_ns}, Pronghorn~\cite{pgh}, SAM~\cite{sam}, the MOOSE thermal hydraulics module, RELAP-7~\cite{relap7} and subchannel~\cite{subchannel}. It is used for coarse mesh multi-dimensional thermal-hydraulics~\cite{pgh}, 1D systems analysis~\cite{sam,relap7} in nuclear reactor analysis, and porous flow simulations~\cite{porous} for underground gas storage and water seepage. The use of consistent fluid properties across fluid flow applications facilitates coupled simulations~\cite{anl_sam_pgh}. The module offers a consistent set of interfaces to implement to create a new fluid property. There are numerous fluid properties of interest in the entirety of all fields of fluid flow simulations, and this is exacerbated by the use of different variable sets depending on the compressibility of the fluid. For single-phase fluids, the following variable sets may be used to compute fluid properties: (pressure, temperature) and (specific volume, specific internal energy). Some properties may also be computed using the (pressure, density) or the (specific volume, specific enthalpy) variable sets. In order to reduce the challenge of adding a new fluid property, properties may be implemented partially.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2024

Transmissive concentrated photovoltaic module with cooling system

A spectrum splitting, transmissive concentrating photovoltaic (tCPV) module is proposed and designed for a hybrid photovoltaic-solar thermal (PV/T) system. The system may be able to fully utilize the full spectrum of incoming sunlight. By utilizing III-V triple junction solar cells with bandgaps of approximately 2.1 eV, 1.7 eV, and 1.4 eV in the module, ultraviolet (UV) and visible light (in-band light) are absorbed and converted to electricity, while infrared (IR) light (out-of-band light) passes through and is captured by a solar thermal receiver and stored as heat. The stored heat energy may be dispatched as electricity or process heat as needed. The tCPV module may have an overall power conversion efficiency exceeding 43.5% for above bandgap (in-band) light under a standard AM1.5D solar spectrum with an average concentration ratio of 400 suns. Passive and/or active cooling methods may be used to keep cells below 110° C. while transmitting >75% of out-of-band light to the thermal receiver, which may attain thermal energy capture at temperatures as high as 500° C. or more. A transparent active cooling system may improve the CPV module efficiency by about 1% (absolute) relative to a passive cooling system by reducing the maximum cell working temperature by about 16° C.

Escarra, Matthew David↗
DOE OSTI2024

Water reflection analysis of encapsulated photovoltaic modules

A method for moisture testing of a fully assembled photovoltaic (PV) module. An assembled PV module is probed with short wave IR probe energy in the range of 1700-2000 nm. Energy reflected from the assembled PV module is collected and directed to a sensor. Noise is removed from a signal of the sensor with reference to the probe energy. Absorption is of the probe energy is determined. The absorption is correlated to moisture in the PV module. A preferred system that carries out the method provides a signal-to-noise ratio (as defined by standard deviation/mean of measured reflectance) of at least 3800.

Fenning, David↗
DOE OSTI2021

Ionizing photon interactions modulate the optical properties of crystals with femtosecond scale temporal resolution

In this work, we continue our study of a new method for the detection of ionizing radiation with the potential for a dramatic improvement in coincidence time resolution (CTR) for time-of-flight positron emission tomography (ToF-PET) using the modulation of a material's optical properties instead of the scintillation mechanism. Our previous work has shown that for non-scintillation materials such as bismuth silicon oxide (BSO) and cadmium telluride (CdTe), their refractive index can be modulated by annihilation photon interactions. Additionally, the ultrafast nature of this process however remains unexplored. The ionizing radiation-induced charge carriers alter the local band structure in these materials, thus changing the complex refractive index. This mechanism is routinely used at the linac coherent light source (LCLS) facility of the SLAC National Accelerator Laboratory to measure x-ray pulse arrival times with femtosecond scale resolution for photon energies between 0.5 and 10 keV. The method described here follows that example by using a frequency chirped visible continuum pulse to provide a monotonic wavelength-to-time mapping by which one can measure the time-dependent refractive index modulation. In addition, we describe an interference-based measurement setup that allows for significantly improved sensitivity while preserving a timing precision of approximately 10 fs (σ) when measuring the arrival time of below 10 keV x-ray pulses with yttrium aluminum garnet (YAG) crystal. The method is presented in the context of ToF-PET application with further discussions on the potential CTR achievable if a similar detection concept is adopted for detecting 511 keV photons. Semi-empirical analysis indicates that the predicted CTR achievable is on the order of 1 ps (FWHM).

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2026

Different Damp-Heat-Induced Series Resistance Degradation Behaviors in Fielded Crystalline Silicon Photovoltaic Modules Due to Difference in Bill of Materials

This case study investigates mono-crystalline silicon modules from underperforming portions of a utility-scale photovoltaic power plant. Field-collected I-V curves and electroluminescence imaging suggested that increased series resistance was a primary factor driving module degradation. Selected modules were removed from the field for further analysis, including incremental damp heat accelerated testing, which confirmed a progression in series resistance degradation. Two distinct cell degradation behaviors became apparent during the investigation. Cross-sectional scanning electron microscopy (with elemental analysis) and scanning spreading resistance microscopy identified key differences between the two degradation mechanisms, primarily grid finger width and contact resistance. Additionally, the study highlights the reliability implications of retest requirements in International Electrotechnical Commission 61215 for material changes and how they may have mitigated the degradation observed at this site.

14 SOLAR ENERGY↗
DOE OSTI2016

Modulation of chorus intensity by ULF waves deep in the inner magnetosphere

Previous studies have shown that chorus wave intensity can be modulated by Pc4-Pc5 compressional ULF waves. In this paper, we present Van Allen Probes observation of ULF wave modulating chorus wave intensity, which occurred deep in the magnetosphere. The ULF wave shows fundamental poloidal mode signature and mirror mode compressional nature. The observed ULF wave can modulate not only the chorus wave intensity but also the distribution of both protons and electrons. Linear growth rate analysis shows consistence with observed chorus intensity variation at low frequency (f <~ 0.3f ce ), but cannot account for the observed higher-frequency chorus waves, including the upper band chorus waves. This suggests the chorus waves at higher-frequency ranges require nonlinear mechanisms. Finally, in addition, we use combined observations of Radiation Belt Storm Probes (RBSP) A and B to verify that the ULF wave event is spatially local and does not last long.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

Chapter 10.3: Reliability and Durability of PV Modules

Each year the world invests tens of billions of dollars or euros in PV systems with the expectation that these systems will last approximately 25 years. Although the disciplines of reliability, quality, and service life prediction have been well established for numerous products, a full understanding of these is currently challenging for PV modules because the desired service lifetimes are decades, preventing direct verification of lifetime predictions. A number of excellent reviews can be found in the literature summarizing the types of failures that are commonly observed for PV modules. This chapter discusses key failure/degradation mechanisms selected to highlight how the kinetics of failure rates can and cannot be confidently predicted. For EVA-encapsulated modules, corrosion is observed to follow delamination, which then allows water droplets to directly contact the metallization. Extended test protocols such as Qualification Plus were created to address the known problems while standards groups update standard tests through the consensus process.

14 SOLAR ENERGY↗