The Experts below are selected from a list of 24282 Experts worldwide ranked by ideXlab platform
Cui Xiang - One of the best experts on this subject based on the ideXlab platform.
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preliminary research on power extraction system laid out along uhv Half Wavelength ac transmission line
Power system technology, 2011Co-Authors: Cui XiangAbstract:A novel way,which is called power extraction system,to supply power for power load around Half-Wavelength AC transmission(HWACT) line by energy extraction from HWACT line is proposed,and the energy extraction is implemented in such a way: a certain length of energy extraction conductors,which are parallel with HWACT line,are laid out beneath the HWACT line.The equivalent source of power extraction system is analyzed,thus the parameters of power extraction system under horizontal conductor arrangement and triangle condctor arrangement of UHV HWACT line are obtained.By means of building mathematical models for UHV HWACT line and power extraction conductors,results of numerical analysis on load characteristics of power extraction system is performed and the suggestions on improving load capacity of power extraction system are put forward.Furthermore,the impacts of single-phase earth fault occurred in UHV HWACT line on power extracton system are analyzed.
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research on steady state operation characteristics of uhv Half Wavelength ac power transmission line
Power system technology, 2011Co-Authors: Wang Lingtao, Cui XiangAbstract:Based on sinusoidal steady-state analytical solution of UHV Half-Wavelength AC power transmission (HWACT) line, the impacts of load characteristics and power factor on its steady-state operation characteristics under inductive load and capacitive load are respectively analyzed. Analysis results show that under normal operation condition, namely severe overload does not occur, the overvoltage level as well as line loss and corona loss of HWACT line are lower than those of traditional transmission lines; the differences of effective values of voltage and current at sending end and receiving end are small, and phase angle of voltage as well that of current at sending end and receiving end are basically reversed. Under the condition of overload, overvoltage appears at the middle of HWACT line. The higher the power factor, the more stable the voltage and current of HWACT line.
Sun Ke - One of the best experts on this subject based on the ideXlab platform.
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economic analysis on uhv Half Wavelength ac power transmission
Power system technology, 2011Co-Authors: Sun KeAbstract:Present condition of energy resources in China is analyzed and the prospect of applying UHV Half-Wavelength AC power transmission in China is discussed.By means of calculating annual cost of unit capacity,the economy of UHV Half-Wavelength AC power transmission is compared with that of UHVDC power transmission,and the results show that the UHV Half-Wavelength AC power transmission is more economical than the ?800 and ?1 000 kV UHVAC power transmission.The social benefit of the UHV Half-Wavelength AC power transmission is analyzed,the upper-limit of control cost for UHV Half-Wavelength AC power transmission is given,and the sensitivity analysis on wiring mode of power plant and transmission capacity is performed.
Xiang Zutao - One of the best experts on this subject based on the ideXlab platform.
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analysis on electromagnetic transient characteristics of uhv Half Wavelength ac transmission system
Power system technology, 2011Co-Authors: Xiang ZutaoAbstract:The geographical positions of main energy resources in China are far from load centers,and the distances between energy resources and load centers are close to Half-Wavelength of power frequencey.UHV Half-Wavelength AC power transmission can be regarded as one of the selectable schemes to send large capacity of electric power via long distance.Based on parameters of UHVAC transmission line in China and refering to the UHVAC transmission system being planned,a model to research UHV Half-Wavelength AC power transmission is built and by which such problems in Half-Wavelength power transmission as power frequency overvoltage,switching overvoltage,overvotlage caused by grounding faults and seconday arc current are simulated and researched.Based on the results from simulation and research,several measures to suppress these kinds of overvoltages and seconday arc current are proposed.
D D Stancil - One of the best experts on this subject based on the ideXlab platform.
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multipath enabled super resolution for rf and microwave communication using phase conjugate arrays
Physical Review Letters, 2004Co-Authors: B E Henty, D D StancilAbstract:We demonstrate experimentally that phase-conjugate techniques can be used to achieve superresolution focusing of electromagnetic waves in a multipath indoor environment at 2.45 GHz. The focusing phenomena was used to direct independent signals to two locations separated by approximately one-Half Wavelength, thereby creating two simultaneous channels at the same frequency. An increase in channel capacity is shown to be achievable by an experimental transmission of a 1 Mbps
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multipath enabled super resolution for rf and microwave communication using phase conjugate arrays
Physical Review Letters, 2004Co-Authors: B E Henty, D D StancilAbstract:We demonstrate experimentally that phase-conjugate techniques can be used to achieve super-resolution focusing of electromagnetic waves in a multipath indoor environment at 2.45 GHz. The focusing phenomena was used to direct independent signals to two locations separated by approximately one-Half Wavelength, thereby creating two simultaneous channels at the same frequency. An increase in channel capacity is shown to be achievable by an experimental transmission of a 1 Mbps signal over two channels created using a four element phase-conjugate array.
Quan Xue - One of the best experts on this subject based on the ideXlab platform.
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low loss frequency agile bandpass filters with controllable bandwidth and suppressed second harmonic
IEEE Transactions on Microwave Theory and Techniques, 2010Co-Authors: Xiu Yin Zhang, Quan Xue, Chi Hou ChanAbstract:This paper presents a novel approach to design frequency-agile bandpass filters with constant absolute bandwidth and passband shape, as well as a suppressed second harmonic. A novel mixed electric and magnetic coupling scheme is proposed to control the coupling coefficient variation. Theoretical analysis indicates that it is able to achieve desired coupling coefficients between the proposed resonators at various frequencies so as to obtain constant absolute bandwidth. Moreover, this Half-Wavelength resonator has a Q higher than the quarter- and Half-Wavelength counterparts, thus resulting in low insertion loss. A filter of this type is designed to validate the proposed idea. To remove the spurious responses of the filter, a method is then introduced to suppress the second harmonic without degrading the passband performance. For demonstration, two frequency-agile filters with 60- and 80-MHz constant absolute bandwidth are implemented with the frequency tuning range from 680 to 1000 MHz. Comparisons of experimental and simulated results are presented to verify the theoretical predications.
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balanced bandpass filters using center loaded Half Wavelength resonators
IEEE Transactions on Microwave Theory and Techniques, 2010Co-Authors: Jin Shi, Quan XueAbstract:This paper presents a balanced filter that is designed by using the center-loaded Half-Wavelength resonator. To demonstrate the design ideas, the differential- and common-mode equivalent Half circuits are built and studied. The proposed technique is novel in the way that the common-mode suppression can be made independent of the differential-mode response in the balanced filter, making use of a center-loaded Half-Wavelength resonator. This is very important to simplify the design and tuning processes of the balanced filters. Making use of this feature, the resonator is not only utilized to design the balanced single-band bandpass filter but also the balanced dual-band bandpass one, possibly being the first to be presented. To demonstrate the design ideas, one single-band and two dual-band balanced filters are presented. The experimental results agree well with the theoretical predictions and simulations.
