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The following topics are dealt with: Power system monitoring and optimization; power system management and power transmission; power generation and power system planning; power generation-thermal power, wind power and solar power; environment protection; power transmission and electromagnetic analysis; power system security and monitoring; energy efficiency and environment-friendly technologies.
A simplified approach to analysis of finite and curved conductor-dielectric periodic (CDP) screen is proposed. The contribution of the element in the real structure is estimated by that of the elaborately constructed virtual infinite planar CDP structure. The analytic results based on Floquet theorem are useable for the proposed approach thus high efficiency and accuracy are obtained. The calculated...
Oilfield development evaluation is one of the key points of oilfield development. It is not only the conclusion of the previous oilfield development course but also the basis of the next step of the oilfield development disposition, and it is the key of the evaluation on the ultimate oilfield development effect. In this paper, the development status of X6 district have been evaluated using three methods:...
The construction of the charging station and battery exchange station can ensure the development of the electric vehicles industry. In the paper, the difference of the charging station and battery-exchange station is investigated, including the economic cost and benefit of the different mode. In addition, the factors affecting the development of the charging station and battery-exchange station is...
Measurements have shown that when the effects of stray field are not negligible the physical Backward-wave or Left-handed transmission line made of lumped L-C components must be modeled by a balanced Composite right/left-handed transmission line model. Corresponding transition frequency not only really exists but also can be estimated by the experiment proposed. The obtained results may have significance...
In this paper, a measurement of the super transient reactance considering the stator winding resistor is put forward, and the steady shortcut current and voltage of two phases in the stator are analyzed as well as relative formula. Based on the data collection system, the super transient reactance in the 3-phase synchronous generator can be obtained. Then correspondent experiment is conducted to testify...
During the combustion of straw, the formation of deposition, which destines to furnace erosion and exerts great influence on safety operation, on heating surface is affected by many factors. The paper studies the influence of speed and amount of air. According to the test: the air speed affects the sedimentary quantity of fly ash and the deposition position; the air amount affects the fuel combustion...
Based on new time frequency algorithm, a new interharmonic analysising method is raised in this paper. The number and approximate frequency of interharmonics is firstly gotten using Least-square algorithm. Then new time frequency algorithm is applied to measure the accurate frequency and magnitude of each interharmonic. The simulation indicates that this method mentioned above is able to measure frequency...
An irreversible Braysson heat engine cycle model, in which the heat transfer obeys a linear heat transfer law between the working fluid and the external heat reservoirs, with heat resistance, heat leak and internal irreversibility is established in this paper. The analytical expressions of power output, efficiency and ecological objective function are derived. These performance parameters are maximized...
The decomposition of sulfur hexafluoride (SF6) in overheated electric equipment at different temperature in low humidity was simulated in the study. SF6 is very stable and not significantly decomposed at 200°C, 250°C and 300°C. SF6 is significantly decomposed at 350°C. SF6 is more easily to be decomposed and decomposed more rapidly at higher temperature.
The computation of circulating currents between parallel conductors is a difficult problem in reactor and transformer design. A direct field-circuit coupling FEM model has been established to analyze the magnetic field of air core power reactor. And the circulating current losses has been calculated based on the magnetic field distribution.
There are geothermal anomalies in Pingdingshan mining area, the average geothermal gradient of up to 4.6°C /100m, which forms geothermal mine disasters. The formation of geothermal anomalies is more closely related to geological structure and groundwater. Using groundwater heat pump technology and air heat exchange system, exploiting the geothermal resources of these mines, which helps to reduce heat...
The fundamental theory and control methods of Active Power Factor Correction (short for APFC) are introduced in this paper. It analyzes and studies the APFC based on the three-phase rectifier. In addition, the simulation model is built on the MATLAB and the results are shown in this paper. The results show that the grids-side input current wave is changed with a sine wave, has the same phase with...
The characteristics of the reaction between nano aluminum and water at low temperature were studied. The effects of temperature and additive on reaction rate were derived. The results indicate that the reaction rate of nano aluminum/water increases with the increase of temperature. Moreover, the reaction rate of nano-aluminum/water is enhanced by polyacrylamide. The reaction mechanism of nano-aluminum/water...
Fractures play an important role in the ultra-low permeability reservoirs. The compatibility between well pattern and the fractures' orientation has a significant impact on the development. Generally speaking, the artificial fractures extend along the natural fractures perpendicular to the minimum principal stress (i.e. parallel to the maximum principal stress). According to the reservoir fluid characteristics...
Based on the dissolved gases analysis and grey relational theory, a fault diagnosis method for transformers is proposed. Fault diagnosis in transformers has several parameters such as the severity of fault and the kind of fault, a lot of typical fault samples are divided into several sets according to the fault type. The practical data are analyzed using grey relational analysis. The experiment showed...
To improve intelligence level of the rural 400V power distribution grid, a new scheme of smart power distribution management is introduced. Smart power distribution cabinets handled by ARM-LINUX based intelligent systems are employed, which have mobile (GPRS/CDMA/3G) networking capability to communicate with the local power dispatch center, so that each cabinet can transfer grid parameters and other...
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