The Experts below are selected from a list of 202539 Experts worldwide ranked by ideXlab platform
Yongqing Meng - One of the best experts on this subject based on the ideXlab platform.
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Experiment on Grid-Connection Process of Wind Turbines in Fractional Frequency Wind Power System
IEEE Transactions on Energy Conversion, 2015Co-Authors: Xifan Wang, Xiaohui Wei, Yongqing MengAbstract:The basic idea of the fractional frequency transmission system (FFTS) is to use lower frequency to reduce the effective electrical length of the ac transmission line, thus increasing its transmission capacity. Because the rotational speeds of the generators in hydro and wind power generation systems are very low, the FFTS is particularly suitable for transmitting electricity produced by renewable energy sources. The fractional frequency wind power system (FFWPS) provides an effective approach for integrating the large-scale and long-distance wind power into the grid. A novel method of the integration of the wind turbines in direct-driven FFWPS is introduced in this paper. A full-power ac-dc-ac converter is used as the grid-Connection device in the experiment, and the experiment results verify the feasibility and effectiveness of the proposed method.
Xifan Wang - One of the best experts on this subject based on the ideXlab platform.
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Experiment on Grid-Connection Process of Wind Turbines in Fractional Frequency Wind Power System
IEEE Transactions on Energy Conversion, 2015Co-Authors: Xifan Wang, Xiaohui Wei, Yongqing MengAbstract:The basic idea of the fractional frequency transmission system (FFTS) is to use lower frequency to reduce the effective electrical length of the ac transmission line, thus increasing its transmission capacity. Because the rotational speeds of the generators in hydro and wind power generation systems are very low, the FFTS is particularly suitable for transmitting electricity produced by renewable energy sources. The fractional frequency wind power system (FFWPS) provides an effective approach for integrating the large-scale and long-distance wind power into the grid. A novel method of the integration of the wind turbines in direct-driven FFWPS is introduced in this paper. A full-power ac-dc-ac converter is used as the grid-Connection device in the experiment, and the experiment results verify the feasibility and effectiveness of the proposed method.
Feng Jing - One of the best experts on this subject based on the ideXlab platform.
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Load Cutting-in Control of Variable-Speed Constant-Freqency (VSCF) Wind-Power Generator
Electric Machines and Control Application, 2009Co-Authors: Feng JingAbstract:Running principle of the grid-Connection Process of doubly-fed generator was discussed.Grid-Connection control strategy of generator was investigated based on stator-oriented vector control technique.Contrasting and simulating the principle of the grid-Connection with load and with no load,the generator of the load cutting-in control can control wind energy in cooperate with wind turbine,which can relieves the stress of windturbine from wind and improve the speed adjustment ability of system.The simulation model of grid-Connection Process of doubly-fed generator was founded.The simulation result verified the impact current was very small and the validity and feasibility of the grid-Connection control strategy of doubly-fed generator.
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Study on the load cutting-in control of the variable-speed constant-freqency(VSCF)wind-power generator
Power System Protection and Control, 2009Co-Authors: Feng JingAbstract:Running principle of the grid-Connection Process of doubly-fed generator is discussed.Grid-Connection control strategy of generator is investigated based on stator-oriented vector control technique .The principles of the grid-Connection with load and on no load are contrasted and analyzed.The generator of the load cutting-in control can control wind energy in cooperation with windturbine , which can relieve the stress of windturbine from wind and improve the speed adjustment ability of system.The simulation model of grid-Connection Process of doubly-fed generator is founded.The simulation result verifies the impact current is very small and the validity and feasibility of the grid-Connection control strategy of doubly-fed generator.
A. Weigand - One of the best experts on this subject based on the ideXlab platform.
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Experimental studies of vortex disConnection and Connection at a free surface
Journal of Fluid Mechanics, 1996Co-Authors: Morteza Gharib, A. WeigandAbstract:An experimental study is presented that examines the interaction of a vortex ring with a free surface. The main objective of this study is to identify the physical mechanisms that are responsible for the self-disConnection of vortex filaments in the near-surface region and the subsequent Connection of disconnected vortex elements to the free surface. The understanding of those mechanisms is essential for the identification and estimation of the appropriate spatial and temporal scales of the disConnection and Connection Process. In this regard, the velocity and vorticity fields of an obliquely approaching laminar vortex ring with a Reynolds number of 1150 were mapped by using Digital Particle Image Velocimetry (DPIV). The evolution of the near-surface vorticity field indicates that the Connection Process starts in the side regions of the approaching vortex ring where surface-normal vorticity already exists in the bulk. A local strain rate analysis was conducted to support this conclusion. DisConnection in the near-surface tip region of the vortex ring occurs because of the removal of surfaceparallel vorticity by the viscous flux of vorticity through the surface. Temporal and spatial mapping of the vorticity field at the surface and in the perpendicular plane of symmetry shows that the viscous flux is balanced by a local deceleration of the flow at the surface. It is found that the observed timescales of the disConnection and Connection Process scale with the near-surface vorticity gradient rather than with the core diameter of the vortex ring.
Xiaohui Wei - One of the best experts on this subject based on the ideXlab platform.
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Experiment on Grid-Connection Process of Wind Turbines in Fractional Frequency Wind Power System
IEEE Transactions on Energy Conversion, 2015Co-Authors: Xifan Wang, Xiaohui Wei, Yongqing MengAbstract:The basic idea of the fractional frequency transmission system (FFTS) is to use lower frequency to reduce the effective electrical length of the ac transmission line, thus increasing its transmission capacity. Because the rotational speeds of the generators in hydro and wind power generation systems are very low, the FFTS is particularly suitable for transmitting electricity produced by renewable energy sources. The fractional frequency wind power system (FFWPS) provides an effective approach for integrating the large-scale and long-distance wind power into the grid. A novel method of the integration of the wind turbines in direct-driven FFWPS is introduced in this paper. A full-power ac-dc-ac converter is used as the grid-Connection device in the experiment, and the experiment results verify the feasibility and effectiveness of the proposed method.