Distributed generation (DG) is increasing its role in modern power systems and the electricity produced by unconventional a.c. and d.c. sources is becoming fundamental in the overall balance. A key element of DG is its mix of different power sources, mostly connected with the grid trough power converters. Since the latter introduce grid perturbations and, at the same time, are affected by the instantaneous grid status, new topologies are being proposed aiming at reducing mutual influences, thus improving the overall efficiency, behaviour and cost. Since cascaded multilevel converters offer significant advantages over the widely diffused PWM two-level converters in terms of harmonic mitigation and low switching frequency. in this chapter a 9-level cascaded inverter suitable for distributed generation and supplied by four fuel cell stacks is proposed and discussed. Such a system operates both in grid-connected and in stand alone mode controlled by a fuzzy logic controller implemented on a FPGA. After a detailed description, system performance are verified and analysed through simulation and experimental results.

关键词：燃料电池；发电机组；电力系统

查看摘要 索取原文[20页]

The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates and integrated heat exchanger technology to collect the heat from the cooling plates (Ref. 1). The next step in the development of this passive thermal approach was the demonstration of the control of the heat removal process and the demonstration of the passive thermal control technology in actual fuel cell stacks. Tests were run with a simulated fuel cell stack passive thermal management system outfitted with passive cooling plates, an integrated heat exchanger and two types of cooling flow control valves. The tests were run to demonstrate the controllability of the passive thermal control approach. Finally, successful demonstrations of passive thermal control technology were conducted with fuel cell stacks from two fuel cell stack vendors.

关键词：燃料电池；温度控制；冷却系统

查看摘要 索取原文[29页]

The fuel cell (FC) is a source of energy that help to avoid pollution and thus contribute to solutions for global warming. This kind of battery is well known since many decades but its research for improving their efficiency is still in progress. Such battery could also be used for specific applications for example in agriculture where many devices operate in a limited area such as tractors, pumps, transfer systems treadmills of agricultural products. One important parameter among others is the diagnostic of their membranes state using real time humidity measurements to improve their efficiency. In this chapter, the basics of FC are first described and their various parameters described. The importance of humidity and its consequences on the efficiency of the FC are also summarized. The different techniques used for measuring the moisture content of the FC with their advantages and disadvantages are also presented before giving the results of measurements performed by our research team at the Nancy University Henri Poincare.

关键词：燃料电池；性能优化

查看摘要 索取原文[24页]

North American, European, and Asian automobile manufacturers project that commercial hydrogen fuel cell-powered light-duty road vehicles will be released by 2015 for general consumer applications. Initially they will be sold in select markets; a much broader market penetration is expected by 2025, when more than 1 million hydrogen fuel cell electric vehicles (FCEVs) are expected to be on the road in the United States. Significant infrastructure implementation, including production capacity, transport, storage, and dispensing, is ongoing to prepare for the commercial introduction of FCEVs. Even more critical for the release of commercial hydrogen vehicles in the United States is the establishment of the Federal Motor Vehicle Safety Standard (FMVSS) for hydrogen-powered vehicles. To ensure international harmony, North American, European, and Asian regulatory representatives are striving to base their respective national regulations on an international safety standard, the Global Technical Regulation (GTR), Hydrogen Fueled Vehicle, which is part of an international agreement pertaining to wheeled vehicles and associated equipment.

关键词：燃料电池；氢；氦；电动汽车；传感器

查看摘要 索取原文[33页]

This report covers the present scenario and the growth prospects of the Global Solar Tracker market for the period 2013-2018. To calculate the market size, the report considers revenue generated from the installation of solar trackers. A detailed study of the geographical segmentation is presented in the report, and the revenue, installed capacity, and growth patterns of solar trackers are also provided. The report also discusses the major products (singleaxis and dual-axis trackers) and technology (PV, CSP, and CPV) based on revenue. In addition, it presents the vendor landscape and a corresponding detailed analysis of the three major vendors in the Global Solar Tracker market. However, the report does not provide the market shares of the vendors; it merely lists the key vendors in the market. In addition, the report discusses the major drivers that influence the growth of the market. It also outlines the challenges faced by vendors and the market at large, as well as the key trends that are emerging in the market.

关键词：太阳能跟踪器；太阳能光伏板；单轴；双轴

查看摘要 索取原文[72页]

Over the past decade, colloidal nanocrystal solar cells have been increasingly investigated as a candidate for low-cost, solution-processed photovoltaics. While colloidal nanocrystals have the potential to combine the superior optical and electrical properties of inorganic semiconductors with the ability for inexpensive, large-area solution-processing manufacturing techniques, significant challenges exist that have limited the performance of devices thus far.One of the most crucial issues yet to be solved is the formation of high-quality Ohmic contacts to the photoactive material that does not damage the nanocrystal film.Many novel thin film device architectures would benefit from a reproducible method of depositing metal electrodes using a non-damaging technique that is compatible with lowtemperature processing requirements. Thermal evaporation of metal electrodes onto thin films of semiconductor nanocrystals can result in damage to the crystal surfaces, diffusion of the metal into the nanocrystals, and shorting of the device through pin-holes in the nanocrystal film. Here we present an alternative method for electrically contacting semiconductor nanocrystal thin films using elastomeric stamps, where transfer of the metal to the substrate does not require an interfacial adhesion layer. We have demonstrated the usefulness of this contact method using a well-studied system of lead chalcogenide quantum dots. The elastomeric stamp contact deposition method not only allows reproducible contacts to materials prone to pin-holes, but also enables thinner layers of active material, which could benefit thin film solar cells that suffer from a short carrier mean free path.

关键词：胶体纳米晶体太阳能电池；电极；光伏发电

查看摘要 索取原文[19页]

Ultrasonic cleaning equipment is a device that uses ultrasound and appropriate solvents to clean complex and delicate items. Ultrasonic cleaning technology uses cavitation and momentum transfer in a liquid medium with frequencies above the human audible limit. It is an -efficient, flexible, durable method of cleaning compared to conventional cleaning methods. This type of equipment has the capability to remove complex contaminants without causing any damage to the surface of the object. The equipment is used across various industries including Healthcare, Automotive, Aerospace and Defense, and Electrical and Electronics.

关键词：超声波清洗设备；适当溶剂；空化；动量传递；清洁高效节能

查看摘要 索取原文[57页]

A transformer monitoring solution is used for monitoring the health of transformers. A monitoring solution helps the end-users to detect and identify any failure in the transformers before it occurs and reduces the cost involved in repair. Utility, Energy and Power, and Oil and Gas industries are the major end-users of these systems.

关键词：变压器；监控；监测；运行状况

查看摘要 索取原文[52页]

The Global Microturbine market is driven by several factors. One of the major drivers in this market is the rising global energy demand. The increasing demand for energy across the globe has a positive influence on the demand for microturbines, which is expected to continue during the remaining years of the forecast period. Another major driver is the increasing demand for electricity from off-grid areas.

关键词：微型燃气轮机；发电机；涡轮机；产生电力；分布式能源

查看摘要 索取原文[70页]

The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two highefficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC-E (Engineering Unit) No. 1 and No. 4. The post-disassembly condition of the sensors is also discussed.

关键词：光机电；传感器；斯特林转换器；性能测量

查看摘要 索取原文[18页]