Photonic crystals have been widely applied to improve the efficiency of solar cells due to its capability to manipulate photon transmission.Both theoretical and experimental research have shown that photonic crystals can significantly improve the absorption and conversion efficiency of solar cells.Solar cells that have photonic crystals back reflectors,intermediate reflectors,and window layers have higher photoelectric conversion efficiency.In this paper,the state-of-the-art applications of PCs in solar ceils are summarized.Various fabrication methods for photonic crystals and their associated performance are discussed.

关键词：光子晶体；太阳能电池；吸收；转换效率

查看摘要 索取原文[5页]

This paper introduces an algorithm called 3-stage current source sorting (3S-CS) in half-unary weighted current cells to improve the linearity of a current-steering digital-to-analog converter (DAC). We show that based on our statistical analysis and simulation results, the proposed algorithm improves the DAC static linearity as well as its dynamic performance.

关键词：电池改进；线性电流源；电能储存

查看摘要 索取原文[9页]

The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratories (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprising of lead acid, lithium-ion or zinc-bromide. Raytheon/KTech has developed an energy storage system that utilizes zinc-bromide flow batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the Raytheon/KTech Zinc-Bromide Energy Storage System. The Raytheon/KTech RK30 Energy Storage System uses twelve RedFlow Zinc-Bromide Battery Modules (ZBMs) and six single phase inverters to sink, store, and supply electrical energy. Each ZBM is rated to hold up to 10kWh and each inverter is rated at 5kW making the system rated at 30kW and 120kWh. The inverters are 208VAC phase to phase inverters and are connected to a delta to wye isolation transformer to allow an electrical wye system interface.

关键词：电池；能源存储系统；电气设备

查看摘要 索取原文[30页]

In order to improve the efficiency of photovoltaic generation as well as the power quality,grid-connected inverters for PV generation research was carried out for photovoltaic maximum power point tracking.Based on some current studies on the incremental conductance method,an advanced incremental conductance control algorithm was proposed,which can track maximum power point rapidly and accurately.The oscillation phenomenon,which exists near the maximum power point,was improved at a great extent,so to the efficiency of photovoltaic cells generation electricity.The inverter control system has an advantage in its high speed and flexibility by applying advanced control algorithm.And the source harmonic current is remarkably reduced.In addition,the power factor is enhanced and the power quality is improved.Finally,according to the principle of inverter control system and based on the analysis on the mathematical model of photovoltaic inverter,a simulation model of that is established based on MATLAB/SIMULINK.

关键词：光伏发电；并网；逆变器；MPPT

查看摘要 索取原文[4页]

Gamma-ray luminosities of some quasar-associated blazars imply jet powers reaching values comparable to the accretion power even if assuming very strong Doppler boosting and very high efficiency of gamma-ray production. With much lower radiative efficiencies of protons than of electrons, and the recent reports of very strong coupling of electrons with shock-heated protons indicated by Particlein- Cell (PIC) simulations, the leptonic models seem to be strongly favored over the hadronic ones. However, the electron-proton coupling combined with the ERC (External-Radiation-Compton) models of gamma-ray production in leptonic models predict extremely hard X-ray spectra, with energy indices (alpha(sup x)) approximately 0. This is inconsistent with the observed 2-10 keV slopes of blazars, which cluster around (alpha(sup x)) approximately 0.6. This problem can be resolved by assuming that electrons can be efficiently cooled down radiatively to non-relativistic energies, or that blazar spectra are entirely dominated by the SSC (Synchrotron-Self Compton) component up to at least 10 keV.

关键词：类星体；X射线谱；加速；伽玛源

查看摘要 索取原文[19页]

In this report we explore claims that phase conjugation of high energy lasers by stimulated Brillouin scattering (SBS) can compensate optical aberrations associated with severely distorted laser amplifier media and aberrations induced by the atmosphere. The SBS media tested was a gas cell pressurized up to 300 psi with SF6 or Xe or both. The laser was a 10 Hz, 3J, Q-switched Nd:YAG with 25 ns wide pulses. Atmospheric aberrations were created with space heaters, helium jets and phase plates designed with a Kolmogorov turbulence spectrum characterized by a Fried parameter, ro, ranging from 0.6 6.0 mm. Phase conjugate tests in the laboratory were conducted without amplification. For the strongest aberrations, D/ro approx. 20, created by combining the space heaters with the phase plate, the Strehl ratio was degraded by a factor of approx. 50. Phase conjugation in SF6 restored the peak focusable intensity to about 30% of the original laser. Phase conjugate tests at the outdoor laser range were conducted with laser amplifiers providing gain in combination with the SBS cell. A large 600,000 BTU kerosene space heater was used to create turbulence along the beam path. An atmospheric structure factor of Cn2 = 5x10-13 m2/3 caused the illumination beam to expand to a diameter 250mm and overfill the receiver. The phase conjugate amplified return could successfully be targeted back onto glints 5mm in diameter. Use of a lenslet arrays to lower the peak focusable intensity in the SBS cell failed to produce a useful phase conjugate beam; The Strehl ratio was degraded with multiple random lobes instead of a single focus. I will review literature results which show how multiple beams can be coherently combined by SBS when a confocal reflecting geometry is used to focus the laser in the SBS cell.

关键词：激光；畸变；放大器；光散射

查看摘要 索取原文[27页]

Battery electric vehicles possess great potential for decreasing lifecycle costs in medium-duty applications, a market segment currently dominated by internal combustion technology. Characterized by frequent repetition of similar routes and daily return to a central depot, medium-duty vocations are well positioned to leverage the low operating costs of battery electric vehicles. Unfortunately, the range limitation of commercially available battery electric vehicles acts as a barrier to widespread adoption. This paper describes the National Renewable Energy Laboratory's collaboration with the U.S. Department of Energy and industry partners to analyze the use of small hydrogen fuel-cell stacks to extend the range of battery electric vehicles as a means of improving utility, and presumably, increasing market adoption. This analysis employs real-world vocational data and near-term economic assumptions to (1) identify optimal component configurations for minimizing lifecycle costs, (2) benchmark economic performance relative to both battery electric and conventional powertrains, and (3) understand how the optimal design and its competitiveness change with respect to duty cycle and economic climate. It is found that small fuel-cell power units provide extended range at significantly lower capital and lifecycle costs than additional battery capacity alone. And while fuel-cell range-extended vehicles are not deemed economically competitive with conventional vehicles given present-day economic conditions, this paper identifies potential future scenarios where cost equivalency is achieved.

关键词：电动电池；电动车辆；氢燃料电池；基准

查看摘要 索取原文[12页]

The intent of the electric Ground Support Equipment (eGSE) demonstration is to evaluate the day-to-day vehicle performance of electric baggage tractors using two advanced battery technologies to demonstrate possible replacements for the flooded lead-acid (FLA) batteries utilized throughout the industry. These advanced battery technologies have the potential to resolve barriers to the widespread adoption of eGSE deployment. Validation testing had not previously been performed within fleet operations to determine if the performance of current advanced batteries is sufficient to withstand the duty cycle of electric baggage tractors. This report summarizes the work performed and data accumulated during this demonstration in an effort to validate the capabilities of advanced battery technologies. This report summarizes the work performed and data accumulated during this demonstration in an effort to validate the capabilities of advanced battery technologies. The demonstration project also grew the relationship with Southwest Airlines (SWA), our demonstration partner at Ontario International Airport (ONT), located in Ontario, California. The results of this study have encouraged a proposal for a future demonstration project with SWA.

关键词：电池材料；先进电池；电动设备

查看摘要 索取原文[30页]

The current rapid advancement of micro-/nanotechnology has gradually shift its focus from the development of discrete devices to the development of more complex integrated systems that are capable of performing multiple functions, such as sensing,actuating/responding, communicating, and controlling, by the integration of individual devices through state-of-the-art microfabrication technologies. Furthermore, it is highly desired for these multifunctional micro-/nanosystems (MNSs) to operate wirelessly and self-sufficiently without the use of a battery, especially in applications such as remote sensing and implanted electronics. This operation scheme will not only extend the life span and enhance the adaptability of these MNSs while greatly reducing the footprint and cost of the entire system, but it will also increase the adaptability of these MNSs to the environment in which they are deployed. As the dimensions of individual devices shrink, the power consumption decreases accordingly to a reasonably low level, so that energy scavenged directly from the ambient is sufficient to drive the devices. The concept of self-powered nanotechnology was first proposed and developed by the Wang research group at Georgia Institute of Technology, with the aim of building a system that operates by harvesting energy from the ambient vicinity of the system and converting it into usable electrical power for wireless, self-sufficient, and independent operations. A typical self-powered MNS should consist of a low-power microcontroller unit, high-performance data-processing/storage components, a wireless signal transceiver, ultrasensitive sensors based on micro-/nanoelectromechancial systems (MEMSs/NEMSs), and most importantly the embedded powering/energy-storage units.

关键词：电池供电；能量收获；纳米技术；能量转换

查看摘要 索取原文[20页]

Hybrids, plug-in hybrids, and battery electrics are conservatively estimated to reach a 5 percent national car park by 2030. Drastic increases in the price of gasoline resulting from oil shocks or major shifts in national energy and environmental policy, however, may push Electric Vehicles (EV) quickly beyond this small share. Should such critical changes occur, EVs will be poised to move beyond their current niche to gain wider scale acceptance and integration into transportation and energy infrastructure. EV battery technology has not improved to the degree needed to achieve the same range mobility as conventionally fueled vehicles. Electric powertrain hybridization and incorporation of regenerative systems such as braking and flywheels are steadily, but only incrementally, improving EV fuel efficiency and range performance. New Corporate Average Fuel Economy (CAFE) regulations in the next decade may drive the light-weighting or downsizing of some vehicle categories to achieve more aggressive fuel economy requirements, especially absent a breakthrough in vehicle battery technology. Light-weighting for battery electrics may be critical. Studies indicate that if primary vehicle mass is reduced between 40-59 percent, battery size and cost may be cut by nearly half without reductions in performance.

关键词：燃料电池；电动工具；智能电网

查看摘要 索取原文[55页]