China wind atlas was made by numerical simulation and the wind energy potential in China was calculated. The model system for wind energy resource assessment was set up based on Canadian Wind Energy Simulating Toolkit...China wind atlas was made by numerical simulation and the wind energy potential in China was calculated. The model system for wind energy resource assessment was set up based on Canadian Wind Energy Simulating Toolkit (WEST) and the simulating method was as follows. First, the weather classes were obtained depend on meteorological data of 30 years. Then, driven by the initial meteorological field produced by each weather class, the meso-scale model ran for the distribution of wind energy resources according each weather class condition one by one. Finally, averaging all the modeling output weighted by the occurrence frequency of each weather class, the annual mean distribution of wind energy resources was worked out. Compared the simulated wind energy potential with other results from several activities and studies for wind energy resource assessment, it is found that the simulated wind energy potential in mainland of China is 3 times that from the second and the third investigations for wind energy resources by CMA, and is similar to the wind energy potential obtained by NREL in Solar and Wind Energy Resource Assessment(SWERA) project. The simulated offshore wind energy potential of China seems smaller than the true value. According to the simulated results of CMA and considering lots of limited factors to wind energy development, the final conclusion can be obtained that the wind energy availability in China is 700～1 200 GW, in which 600～1 000 GW is in mainland and 100～200 GW is on offshore, and wind power will become the important part of energy composition in future.展开更多
This paper addresses the development and testing of a remotely controlled boat platform with an innovative air-ventilated hull. The application of air cavities on the underside of ship hulls is a promising means for r...This paper addresses the development and testing of a remotely controlled boat platform with an innovative air-ventilated hull. The application of air cavities on the underside of ship hulls is a promising means for reducing hydrodynamic drag and pollutant emissions and increasing marine transportation efficiency. Despite this concept＇s potential, design optimization and high-performance operation of novel air-cavity ships remain a challenging problem. Hull construction and sensor instrumentation of the model-scale air-cavity boat is described in the paper. The modular structure of the hull allows for easy modifications, and an electric propulsion unit enables self-propelled operation. The boat is controlled remotely via a radio transmission system. Results of initial tests are reported, including thrust, speed, and airflow rate in several loading conditions. The constructed platform can be used for optimizing air-cavity systems and testing other innovative hull designs. This system can be also developed into a high-performance unmanned boat.展开更多
Wind energy is renewable energy which is an alternative to the challenge facing the worlds electricity sector to reduce the conventional electricity that is based on burning fossil fuels. Mexico recognizes the need to...Wind energy is renewable energy which is an alternative to the challenge facing the worlds electricity sector to reduce the conventional electricity that is based on burning fossil fuels. Mexico recognizes the need to undertake sustainable development activities that promote the welfare of present and future generations. This country has a significant potential whose exploitation could meet up to 5% of electricity needs. The region of the Isthmus of Tehuantepec in Oaxaca State has been characterized as the region with the highest wind resources in Mexico. This article discusses the current state of wind energy in this region from an economic perspective, environmental policy and to promote greater participation in the national grid.展开更多
The paper presents an innovative renewable energy-load management technology, which is currently being developed as a prototype, in preparation for potential large-scale implementation in power systems. The new techno...The paper presents an innovative renewable energy-load management technology, which is currently being developed as a prototype, in preparation for potential large-scale implementation in power systems. The new technology employs controlled motion of large weights, which are being maneuvered （up and down） through the system peak/off-peak demand pattern. The load management scheme is similar to the pumping storage systems, but uses large weights instead of water and, therefore, is more suited to the operating environment in Saudi Arabia, in which water is relatively scarce. A portion of the off-peak valley-filling energy is supplied from wind-driven generators, which adds to the green energy component of the scheme. The controlled motion aspect of the new technology is based on partial implementation of previously published ideas by the authors as well as a registered patent. The paper describes the theoretical and analytical features of the introduced renewable energy-load management technology, and dwells on its practical implementation features.展开更多
Up to now legislation of economical usage of Estonian sea shelf is lacking, what breaks development of wind farms. Therefore it is expedient to look the potential of wind resources and prablems to use it. In this pape...Up to now legislation of economical usage of Estonian sea shelf is lacking, what breaks development of wind farms. Therefore it is expedient to look the potential of wind resources and prablems to use it. In this paper the potential resource of four characteristic offshore regions in Estonia are assessed. Two different approaches have been used to assess the dynamic quality of the wind power, both of which lead to the same result. The dynamic quality of the load of the grid is also assessed since any consumer will be affected by the total influence of both these dynamic processes. These processes do limit the usage of wind power due to peculiarities of the Estonian electrical grid.展开更多
In recent years,China has made significant achievements in optimizing its energy structure and tapping into renewable energy.Wind power,in particular,has been doubled in its development year by year between 2005-2009....In recent years,China has made significant achievements in optimizing its energy structure and tapping into renewable energy.Wind power,in particular,has been doubled in its development year by year between 2005-2009.However,wind power develops too fast,which is not harmonious with the power system,the industry structure and the policy mechanism.Therefore,it is necessary to find the fundamental causes for the issue.Based on the inherent features and practical issues of wind power development in China,the role of wind power in energy development is put forward through probing logically into three perspectives,i.e.energy utilization,energy development and the ultimate objectives of wind power development.The current wind power development should be grounded on the improvement of wind power industrialization system,the smart grid and the research on new energy storage technology so as to lay firm foundations for large-scale development of wind power in the future.展开更多
This paper deals with various aspects of modeling, simulation, analysis, and control ofa SRG （switched reluctance generator） in different modes of operation. Excitation method of such a generator is shortly describe...This paper deals with various aspects of modeling, simulation, analysis, and control ofa SRG （switched reluctance generator） in different modes of operation. Excitation method of such a generator is shortly described. The output power of the SRG is controlled so that it can track the maximum output power of a wind turbine drive applications. Also, the output generator voltage is stabilized under either load or wind speed variations. Basic operational characteristics of a three-phase 6/4 SRG are developed through experimental observation. Meanwhile, the real-time operation was implemented in a DSP （digital signal processor） environment. The simulation of the complete system model has been obtained using the Matlab/Simulink software. A good agreement between experimental and simulation results has been observed which supports the validity of the proposed analysis.展开更多
文摘China wind atlas was made by numerical simulation and the wind energy potential in China was calculated. The model system for wind energy resource assessment was set up based on Canadian Wind Energy Simulating Toolkit (WEST) and the simulating method was as follows. First, the weather classes were obtained depend on meteorological data of 30 years. Then, driven by the initial meteorological field produced by each weather class, the meso-scale model ran for the distribution of wind energy resources according each weather class condition one by one. Finally, averaging all the modeling output weighted by the occurrence frequency of each weather class, the annual mean distribution of wind energy resources was worked out. Compared the simulated wind energy potential with other results from several activities and studies for wind energy resource assessment, it is found that the simulated wind energy potential in mainland of China is 3 times that from the second and the third investigations for wind energy resources by CMA, and is similar to the wind energy potential obtained by NREL in Solar and Wind Energy Resource Assessment(SWERA) project. The simulated offshore wind energy potential of China seems smaller than the true value. According to the simulated results of CMA and considering lots of limited factors to wind energy development, the final conclusion can be obtained that the wind energy availability in China is 700～1 200 GW, in which 600～1 000 GW is in mainland and 100～200 GW is on offshore, and wind power will become the important part of energy composition in future.
基金Foundation item： Supported by the National Science Foundation （CMMI-1026264 and EEC-1157094）.
文摘This paper addresses the development and testing of a remotely controlled boat platform with an innovative air-ventilated hull. The application of air cavities on the underside of ship hulls is a promising means for reducing hydrodynamic drag and pollutant emissions and increasing marine transportation efficiency. Despite this concept＇s potential, design optimization and high-performance operation of novel air-cavity ships remain a challenging problem. Hull construction and sensor instrumentation of the model-scale air-cavity boat is described in the paper. The modular structure of the hull allows for easy modifications, and an electric propulsion unit enables self-propelled operation. The boat is controlled remotely via a radio transmission system. Results of initial tests are reported, including thrust, speed, and airflow rate in several loading conditions. The constructed platform can be used for optimizing air-cavity systems and testing other innovative hull designs. This system can be also developed into a high-performance unmanned boat.
文摘Wind energy is renewable energy which is an alternative to the challenge facing the worlds electricity sector to reduce the conventional electricity that is based on burning fossil fuels. Mexico recognizes the need to undertake sustainable development activities that promote the welfare of present and future generations. This country has a significant potential whose exploitation could meet up to 5% of electricity needs. The region of the Isthmus of Tehuantepec in Oaxaca State has been characterized as the region with the highest wind resources in Mexico. This article discusses the current state of wind energy in this region from an economic perspective, environmental policy and to promote greater participation in the national grid.
文摘The paper presents an innovative renewable energy-load management technology, which is currently being developed as a prototype, in preparation for potential large-scale implementation in power systems. The new technology employs controlled motion of large weights, which are being maneuvered （up and down） through the system peak/off-peak demand pattern. The load management scheme is similar to the pumping storage systems, but uses large weights instead of water and, therefore, is more suited to the operating environment in Saudi Arabia, in which water is relatively scarce. A portion of the off-peak valley-filling energy is supplied from wind-driven generators, which adds to the green energy component of the scheme. The controlled motion aspect of the new technology is based on partial implementation of previously published ideas by the authors as well as a registered patent. The paper describes the theoretical and analytical features of the introduced renewable energy-load management technology, and dwells on its practical implementation features.
基金Acknowledgment The authors thank the Estonian Science Foundation as mediator of the international grant EMP 53
文摘Up to now legislation of economical usage of Estonian sea shelf is lacking, what breaks development of wind farms. Therefore it is expedient to look the potential of wind resources and prablems to use it. In this paper the potential resource of four characteristic offshore regions in Estonia are assessed. Two different approaches have been used to assess the dynamic quality of the wind power, both of which lead to the same result. The dynamic quality of the load of the grid is also assessed since any consumer will be affected by the total influence of both these dynamic processes. These processes do limit the usage of wind power due to peculiarities of the Estonian electrical grid.
文摘In recent years,China has made significant achievements in optimizing its energy structure and tapping into renewable energy.Wind power,in particular,has been doubled in its development year by year between 2005-2009.However,wind power develops too fast,which is not harmonious with the power system,the industry structure and the policy mechanism.Therefore,it is necessary to find the fundamental causes for the issue.Based on the inherent features and practical issues of wind power development in China,the role of wind power in energy development is put forward through probing logically into three perspectives,i.e.energy utilization,energy development and the ultimate objectives of wind power development.The current wind power development should be grounded on the improvement of wind power industrialization system,the smart grid and the research on new energy storage technology so as to lay firm foundations for large-scale development of wind power in the future.
文摘This paper deals with various aspects of modeling, simulation, analysis, and control ofa SRG （switched reluctance generator） in different modes of operation. Excitation method of such a generator is shortly described. The output power of the SRG is controlled so that it can track the maximum output power of a wind turbine drive applications. Also, the output generator voltage is stabilized under either load or wind speed variations. Basic operational characteristics of a three-phase 6/4 SRG are developed through experimental observation. Meanwhile, the real-time operation was implemented in a DSP （digital signal processor） environment. The simulation of the complete system model has been obtained using the Matlab/Simulink software. A good agreement between experimental and simulation results has been observed which supports the validity of the proposed analysis.
