架空输电线路故障检测器供能电源的设计

提出一种通过特制线圈从高压侧一次母线取能与蓄能电池相结合的设计方案,作为架空线路故障检测器的电源供给,介绍了该方案的原理和设计要点。实验证明,该电源方案在母线正常电流范围内可提供稳定电能,在短路或断电的故障状态下也能正常工作,并在大电流的情况下能可靠地保护后级电路,提供稳定电压输出,从而有效解决了架空输电线有源电子设备的供能问题。

Outage Performance of Cognitive DF Relaying Networks Employing SWIPT

In this paper, the outage perfor- mance of a cognitive relaying network over Nakagami-m fading channels, employing simultaneous wireless information and power transfer （SWIPT） technology is analyzed and evaluated. The operation of this network is considered in conjunction with the convention- al decode-and-forward （DF） and incremental DF （IDF） protocols. For the conventional DF protocol, it is assumed that there is no direct link between the secondary transmitter （S） and the secondary destination （D）, while （for both protocols） after harvesting energy, the relay node （R） always helps to forward the resulting signal to D. However, for the IDF protocol, R assists in relaying S＇s information to D only when the direct communication between S and D has failed. Furthermore, for both DF and IDF protocols, we assume there is no power supply for R, and R harvests energy from the transmitted signal of S. We derive exact ana- lytical expressions for the outage probability at D in DF and IDF protocols, respectively, in terms of the bivariate Meijer＇s G-function. Performance evaluation results obtained by means of Monte-Carlo simulations are also provided and have validated the correctness of the oroDosed analysis.

Traffic-prediction-assisted dynamic power saving mechanism for IEEE 802.16e wireless MANs

How to reduce the energy consumption powered mainly by battery to prolong the standby time is one of the crucial issues for IEEE 802.16e wireless MANs.By predicting the next downlink inter-packet arrival time,three traffic-prediction-assisted power saving mechanisms based on P-PSCI,i.e.,PSCI-PFD,PSCI-ED and PSCI-LD,were proposed.In addition,the corresponding adjustment strategies for P-PSCI were also presented when there were uplink packets to be transmitted during sleep mode.Simulation results reveal that compared with the sleep mode algorithm recommended by IEEE 802.16e,the proposed mechanism P-PSCI can improve both energy efficiency and packet delay for IEEE 802.16e due to the consideration of the traffic characteristics and rate changes.Moreover,the results also demonstrate that PSCI-PFD (a=-2) significantly outperforms PSCI-ED,PSCI-LD,and the standard sleep mode in IEEE 802.16e is in terms of energy efficiency and packet delay.

Economic Impact of Renewable Generation on the Cost of Energy Supply

This article presents an analysis of the economic impact of non-dispatchable generation on the cost of the energy supply. It aims to analyze the economic impact of the renewable generation in Spanish production and thus to help prospective investors in renewable generation projects to analyze the situation of the Spanish electricity market. With that target, the current situation in Spain is shown and then using a MATLAB program, the economic impact of the renewable generation on the Spanish daily is analyzed.

Solar Radiation and Temperature Measurement of Solar Dish Concentrator System

Concentrating solar power （CSP） technologies could be one of the major contributor to worlds future energy needs and which would be cheap and clean sources of energy. This would improve energy utilization, higher conversion efficiency with reliable and affordable supply of electricity to the public. The proposed approach is using 18 inch diameter of solar dish concentrator to measure the solar radiation using the aluminium foil as a reflector. In this paper, solar radiation is collected to investigate the solar fraction on incoming solar energy in wet climate.

Energy Flexibility in the Power System： Challenges and Opportunites in Philippines

Energy flexibility can address the challenges of large scale integration of renewable energy resources and thereby increasing imbalance in the power system. Flexible power system can provide reliable supply, low electricity cost and sustainability. Various situations and factors influence the adoption of the flexibility solutions, such as flexible electricity generation, demand-response, and electricity storage. This paper tries to analyze the current energy flexibility solutions and the factors that can influence the energy flexibility adoption. This paper takes Philippines as case study to provide an overview of the current condition of the Philippines＇ power system and discuss the energy flexibility in the Philippines＇ power system. A further discussion and recommendation is conducted in the end of the paper.

On Issues of Large-Scale and Long-Distance Transmission of Wind Power

While having constantly developed for five years,China's wind power meets its bottleneck of further development in fast-growing areas due to the insufficient market accommodation.In contrast,the Central China and the East China have experienced the shortage of coal,oil and natural gas for power generation in recent winters.Hence,how to handle the discrepancy between insufficient accommodation and short energy supply has become the focus of attention both domestically and abroad.Taking Jiuquan Wind Power Base as an example,the reverse distribution between the energy resources and the consumer market,the wind power accommodation and the energy transmission are analyzed;the necessity and feasibility of long-distance power transmission are also discussed,which presents a technical roadmap for the long-distance transmission of thermal and wind power in combination.

Issues and Solutions for China's Photovoltaic Power Industry

Solar energy is an important renewable energy.Developing photovoltaic power will not only relieve the energy supply-demand contradiction and optimize the energy structure,but also help to restructure this industry.This paper analyzes the status quo and the development prospects of China's photovoltaic power industry and its existing issues,and puts forward some suggestions and solutions for its healthy and orderly development.

Life Cycle Evaluation of Energy Supply Technologies in China by Energy Chain Multi Layered Model

China has a large potential to reduce CO2 emission in the Asian region. In this study, life cycle analyses of energy supply technologies in China were evaluated for enforcing the clean development mechanism （CDM）. Wind power, integrated coal gasification combined cycle （IGCC）, natural gas combined cycle （NGCC）, and ultra super critical power plant （USC） were chosen as new power generation technologies. The system function of the developed model was enhanced to extend coverage to new technologies for power generation systems in China. CO2 intensities, energy profit ratios, and CO2 emission reductions are estimated based on the assumption that these power plants were constructed at Shanxi, Xinjiang, and Shanghai. Wind power showed the best results with regard to CO2 intensity and energy profit ratio. However, it also has some disadvantages with regard to the utilization factor and the lifetime. It is considered that wind power will become an important part of CDM activities as the utilization factor and the lifetime improve. An NGCC using a natural gas pipeline was found to be most advantageous in reducing CO2 emission. IGCC and USC were inferior to NGCC with regard to energy profit ratios and CO2 emission reductions.

Design Methods for Improving the Performance and Thermal Stability of Radar

The radar power supplies exhibit a complex electronics. The development of more and more compact systems leads to master the interaction between different parts of the power supply while reducing electronic circuits, magnetic and thermal couplings from the constitutive circuitry. The consideration of these phenomena is very difficult at the design of the power supply. This paper presents two complementary methods based first on a circuitry model for the quantification of heat sources and secondly on finite element model for heat diffusion. This approach can help a designer in the goal of improving the performances and thermal stability of radar tied to the supply circuit subset.

Development and Commercialization of New Autonomous Low Power Systems for Energy Harvesting

This paper evaluates new technologies for energy harvesting from the environment. We assess the reliability, accuracy, and autonomy of low power electronic devices, their market opportunities, and their ability to enhance sustainable development. For small, portable applications that need long lifetime energy supply systems, size, width, finite energy lifetime, and the need for replacement are important drawbacks. New supply alternatives should be explored that are able to make recharging easier or to remove battery dependence altogether. A new trend in the energy sources for low power applications has emerged in recent years, involving the harvesting of the energy available in the environment to supply power for electronic applications instead of using battery technologies that provide only short, finite amounts of energy. In this paper, we describe an all-purpose module of energy harvesting from mechanical, thermal, solar and RF energy sources developed at the University of Barcelona. We provide proof of concept in order to incorporate this novel energy technology in a wide range of applications and environments.

An Activity in Japan for Realizing CO2-Free Hydrogen Global Supply Chains

The current basic energy plan of Japan was authorized in the Cabinet in June 2010, in which ambitious energy and environmental targets and policies giving nuclear power a pivotal role toward 2030 were described. At present, the Japanese government has been forced to review the basic energy plan in the wake of the great east Japan earthquake occurred on March 11, 2011 followed by the severe accident at the nuclear power plants in Fukushima. Before the disaster, the IAE （institute of applied energy） had realized that it was not clear how CO2-free hydrogen would contribute to solving various energy and environmental issues, or that prospects were not clear for large demand of CQ-free hydrogen other than FCVs （fuel cell vehicles）. In this connection, the authors organized a voluntary ＂Concept Study Group （in short）＂ in March 2011 and held four meetings until the end of March 2012. Through the quantitative studies using IAE＇s simulation model （GRAPE）, the common recognition was built in the concept study group that hydrogen could contribute to energy security and increase in zero-emissions electric power ratio in Japan. It was also estimated that global CO2-free hydrogen supply chains could be realized by degrees after 2020. Based on these results, the authors made a proposal that hydrogen should be added in the primary energy constitution for new basic energy plan to the Japanese government because imported hydrogen could be considered as a pseudo-primary energy like LNG （liquefied natural gas）. Now, the succeeding ＂Action Plan Study Group （in short）＂ has been held focusing on hydrogen demand in various applications, future pictures of CO2-free hydrogen chains and road maps. Activity results of the ＂Concept Study Group＂ are shown here.

Statistical Analysis and Energy Planning of Electric Power Supply Systems with Intelligent Control

The study presents possibilities for reconstruction of electric power supply systems in Bulgarian Black Sea resorts and possibilities to use statistical methods in energy planning. The paper shows the use of classic statistical methods in combination with advanced digital measurement systems in order to obtain the correlation dependencies, nature of energy consumption and opportunities for energy forecasting. The main purpose of the study is to obtain statistical dependencies of the nature of power consumption and correlations between electricity consumption and ambient temperature in order to improve the accuracy of energy planning. The analysis includes application of energy management systems for proper energy planning, improving economical efficiency and reducing power and energy losses.

Considerations of Electricity Supply Quality in Spain

The quality of supply in Spain is regulated by Act 54/1997 as the basic standard and further developed by Royal Decree 1955/2000, among others. Also this law （1997） introduces the division between generators, distribution companies and retailers. The aim of this paper is to provide an overview of the fundamental parameters to be taken into account when examining the status of national regulations in Spain on the quality of electricity supply, in addition to describing the various agents intervening in these. There are two more aspects to consider： the guarantee of supply and energy is provided at the lowest cost to consumers. The authors propose to include phase-shifting transformers at specific strategic points, in accordance with power flow control principles in parallel circuits. Finally, it can be concluded that Royal Decree 222/2008 needs reviewing and applying effectively, as do modifications to Royal Decree 1995/2000 providing remuneration that effectively induces electricity companies to invest in their networks, and ends with ＂a well-paid electricity company is obliged to invest in network improvements＂.

Modeling Relative Humidity Effects on Power Electronic Performance

Variations in the behavior of power supplies caused electrical behavior dependence with environmental conditions. by environmental conditions require accurate characterization of the This paper introduces models to help predict relative humidity （Rtt） and other environmental factors influence on sensitive circuitry in power electronic systems. The resistivity and permittivity of an insulator have been modeled using different water contents i.e. RH, such model also included the mechanical properties of the design. An application example of a high power density, high voltage DC-DC converter is used to verify the results.

Research and development of micro electret power generators

As the size of the electronic system continuously reduces, characteristics of small volume, light weight, high energy it is very important to develop micro power generator, which has density and continuous energy supplying. Vibration energy exists widely in daily environment. Micro vibration power generator can harvest and exchange the vibration energy to the electrical energy. Micro electret power generator is one kind of the power generators for harvesting vibration energy and has been paid much attention by researchers. This paper describes the development and status of micro electret power generators, including electret materials and charging methods, vibration energy harvesting structures and conversion efficiency improvement.