Abstract: A Multiple Direction Broad Frequency Band Piezoelectric Energy Harvester Pages 1-10 Author Hongbing WangChunhua SunZhirong LiYiping Zhan A multiple direction broad frequency band piezoelectric energy harvester is proposed for harvesting ambient vibration energy with a variable frequency in different directions. The harvester is composed of eight cantilevers which point to different direction. The single cantilever consists of a base, two ceramic pieces and a proof mass which would be glued together. The finite element model of the harvester is constructed and the effects of structure parameters of the harvester on effective work frequency, electricity generating capability and maximal stress value are analyzed. The results indicate the effective work frequency scope of the harvester is about 13-20Hz. The harvester can harvest relatively more energy in different excitation. The electric potential of a harvester is about 720.136V at the ambient load of 400Pa and the harvester is well suited for some wireless communication systems. PubDate: 2016-0
Abstract: Special Instrument Transformers for Renewable Energy and Rural Electrification Pages 11-18 Author Worawut Sae-KokDavid XuJinyong ChenNicholas PowersMathew Pau This paper presents the solutions provided by Station Service Voltage Transformer (SSVT) for applications in renewable energy and rural electrification. A SSVT is a special hybrid type of instrument transformer product with features of a high voltage inductive voltage transformer and a distribution transformer to offer a compact, reliable power source. Using SSVT for renewable applications, e.g. wind and solar, can provide a reliable, convenient source of control power for independent operations in remote areas. For rural electrification application, SSVT serves as a mini-substation, stepping down the power supply directly from the high voltage transmission line to low voltage or medium voltage output in one step to provide power source to small residential areas without the large investment, meanwhile reduce the required space and shorten the time duration for construction of a typical substation. ABB has delivered many SSVT products both oil and SF6 in substations around the world. Many of them are used for the above-mentioned applications which are recommended for wide use in the future grid. PubDate: 2016-0
Abstract: Design and Implementation of a Novel Two-Stage LED Driver Pages 19-25 Author Yu-En W This paper presents a novel two-stage LED driver system which possesses two sets output source to keep the brightness of LED load. The first-stage of the proposed system is the power factor correction (PFC) circuit which possesses fully voltage range (85~265V, 50/60Hz) and is implemented by boost converter. It operated in boundary conduction mode (BCM) to improve the power factor and the output voltage is 400V. The second-stage of it is the forward converter which is used to convert input voltage 400V to 30V. The converter designed the third winding to transfer the energy of magnetizing inductance to the second winding for maintaining the output voltage stability. Finally, a two-stage driver circuit is implemented to verify the functionality and feasibility of the proposed system. PubDate: 2016-0
Abstract: Quantifying the Energy-Storage Benefits of Controlled Plug-in Electric Vehicle Charging Pages 26-34 Author Xiaomin XiRamteen Sioshans Flexibility in plug-in electric vehicle (PEV) charging can reduce PEV charging costs. Moreover, controlled PEV charging can be viewed as a limited form of energy storage, insomuch as charging loads are shifted from high-cost periods to lower-cost ones. Energy storage that is used for generation shifting is used in much the same manner. In this paper, we study these benefits of PEV charging, demonstrating that controlled PEV charging can reduce generation costs. We also determine how much energy storage would be needed to provide the same cost-reduction benefits that the PEV fleet does. PubDate: 2016-0
Abstract: Analysis of Recover Waste Heat for Thermal Power Plant Using Ejector Pages 35-41 Author Haiwen WangJianxing RenJunjie ZhangKaikai Zh The ejector is a new type of heating device. This paper that based on the working principle of ejector and coefficient of performance indicators, expounds the application of pressure regulator and mixed heater, and recovers steam exhaust of deaerator in coal-fired power plant. Under the design conditions of the equipment, we conduct a series of research and obtain the benefits that saving coal 700t, reducing the emission of CO2 308t, SO214t, dust 10.5t and ash 308t annually. The results show that the application of ejector in thermal plant improves the economics of unit and obtains the outstanding environment benefits. PubDate: 2016-0
Abstract: Transient Stability Improvement of a Multi-Machine Power System by Using Superconducting Fault Current Limiters Pages 42-47 Author Jian FangYuwei DaiLei ChenGuocheng L In regard to the rapid development of high-temperature superconducting materials, electric power applications of superconductivity have attracted more and more attention from home and abroad. In regard to superconducting fault current limiter (SFCL) known as one of the best countermeasures to solve the technical problems related to a short-circuit fault, its practical applications have covered power transmission and distribution systems. In this paper, it is devoted to study the application of flux-coupling type SFCLs in improving the transient stability of a multi-machine power system. Related theory deduction and simulation calculation analysis are carried out, and the results demonstrate that, using the flux-coupling type SFCLs can effectively reduce the imitated multi-machine system’s power-angle fluctuations and increase the critical fault clearance time. As a result, the improvement of the transient stability can be well achieved. PubDate: 2016-0
Abstract: Technology Research for CO2 Capture from Coal-fired Flue Gas Pages 48-52 Author Liangfei LuoFangqin LiHaigang JiHaiwen Wan In recent years, global warming has been a serious threat to human society, the survival environment and economic development. So it is urgent to CO2 emissions reduction. In this paper, through a comprehensive analysis of the current status of carbon dioxide capture technology, by comparing the combustion of carbon dioxide capture technology,this paper discusses the advantages and disadvantages of each technology. At the same time, the latest progress and development trend of carbon dioxide capture technology are introduced. PubDate: 2016-0
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