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风力发电系统的电力电子控制
Wind energy has mushroomed into a mature and booming global green business while generation costs have fallen dramatically. Modern wind turbine technologies have been improved significantly in their power rating, efficiency and reliability. Global wind energy capacity is up to 196.6 GW at the end of 2010. This Chapter covers 1. mathematical models for wind turbines such as wind turbine (WT) with doubly fed induction generator (DFIG) and WT with direct-drive permanent magnet generator (DDPMG); 2. small signal stability analysis and nonlinear control using power electronic back-to-back converters, which are very similar to those of UPFC and VSC HVDC; 3. dynamic equivalent modeling of wind farms; 4. and wind farm interconnection with power grid via VSC HVDC link.
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通过测量燃料电池膜的含水量优化其性能
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.
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海洋热能转换的技术准备(OTEC)
The decreasing supply, and increasing cost, of fossil-fuel based energy has intensified the search for renewable alternatives. Although traditionally more expensive, renewable energy sources have many incentives, including increased national energy security, decreased carbon emissions, and compliance with renewable energy mandates and air quality regulations. In remote islands where increased shipping costs and economies of scale result in some of the most expensive fossil-fuel based energy in the world, renewable energy sources are particularly attractive. Many islands, including Guam and Hawaii, contain strategic military bases with high energy demands that would greatly benefit from an inexpensive, reliable source of energy independent of the fossilfuel based economy. The oceans are natural collectors of solar energy and absorb billions of watts of energy from the sun in the form of solar radiation daily.
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ConnecticutNutmeg燃料电池公共汽车项目
This report summarizes the experience and early results from a fuel cell bus demonstration funded by the Federal Transit Administration (FTA) under the National Fuel Cell Bus Program (NFCBP). A team led by the Northeast Advanced Vehicle Consortium and UTC Power developed a next-generation fuel cell electric bus for demonstration. A total of four buses are being operated in service by Connecticut Transit in Hartford. The National Renewable Energy Laboratory has been tasked by FTA to evaluate the buses in service. This report documents the early development and implementation of the buses and summarizes the performance results through May 2012.
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聪明的想法:被动式太阳能建筑
Significant federal involvement in solar building technology began with a series of acts of Congress passed in 1974; the Solar Heating and Cooling Demonstration Act; the Energy Reorganization Act; the Solar Energy Research, Development and Demonstration Act; and the Federal Non-Nuclear Energy Research and Development Act. These acts established programs for solar-related research and development in various fields. In 1977, the Department of Energy Reorganization Act established DOE and placed all solar energy programs under its authority. Over the years, the DOE Solar Buildings Technology Program has developed in response to the needs of the building industry and to opportunities opened up by new technology. From 1974 to 1980, a wide range of federal solar activities existed, including scientific research on many different fronts, demonstration projects, market research, design assistance, community programs, professional education, and public information. Since 1980, a smaller federal solar research and development program has emphasized new technology. The Solar Buildings Technology Program currently includes research and development programs in both active and passive solar; this overview focuses on activities in the latter.
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太阳能卫星重新利用
The selling price of electrical power varies with time. The economic viability of space solar power is maximum if the power can be sold at peak power rates, instead of baseline rate. Price and demand of electricity was examined from spot-market data from four example markets: New England, New York City, suburban New York, and California. The data was averaged to show the average price and demand for power as a function of time of day and time of year. Demand varies roughly by a factor of two between the early-morning minimum demand, and the afternoon maximum; both the amount of peak power, and the location of the peak, depends significantly on the location and the weather. The demand curves were compared to the availability curves for solar energy and for tracking and non-tracking satellite solar power systems in order to compare the market value of terrestrial and solar electrical power. In part 2, new designs for a space solar power (SSP) system were analyzed to provide electrical power to Earth for economically competitive rates. The approach was to look at innovative power architectures to more practical approaches to space solar power. A significant barrier is the initial investment required before the first power is returned. Three new concepts for solar power satellites were invented and analyzed: a solar power satellite in the Earth-Sun L2 point, a geosynchronous no-moving parts solar power satellite, and a nontracking geosynchronous solar power satellite with integral phased array. The integral-array satellite had several advantages, including an initial investment cost approximately eight times lower than the conventional design.