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
Due to randomness of wind generator＇s availability, power system planners have big concern on EEG （expected energy generation） and system reliability of power system with wind generators. This paper presents a meth...Due to randomness of wind generator＇s availability, power system planners have big concern on EEG （expected energy generation） and system reliability of power system with wind generators. This paper presents a methodology to evaluate the EEG as well as overall LOLP （loss of load probability）, which is an index for system reliability of multi-area interconnected systems with wind generators, as well as conventional fossil fuel based generating units. The proposed model is also capable of tracking the energy export incorporating the multi-state probability model for wind generator which output varies with time and season.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
With the increasing number of wind farms in power systems, the scheduling of a single wind farm needs to be improved. For this end, this paper proposes an optimal short-term load dispatch strategy for a single wind fa...With the increasing number of wind farms in power systems, the scheduling of a single wind farm needs to be improved. For this end, this paper proposes an optimal short-term load dispatch strategy for a single wind farm. Firstly, considering the large number of wind units and the high dimensionality of the scheduling solutions, we analyze the unit load characteristics, from which we extract the unit load characteristic matrix, and then classify the wind power units with the FCM fuzzy clustering algorithm. Secondly, we define the running loss indicator and action loss indicator. Based on the prediction of wind power and the load instructions, we establish a unit commitment model in wind farm, and solve the model using a combination of the fuzzy clustering algorithm and genetic algorithm, which overcomes the difficulty of the high dimensionality of the solution in the wind farm scheduling problem, to obtain the optimal scheduling strategy. Finally, through the simulation of the scheduling strategy for a 45 MW wind farm, we demonstrate the feasibility and effectiveness of the proposed strategy.展开更多
A study of the heat transfer about the heating surface of three commercial 300 MWe CFB boilers was conducted in this work. The heat transfer coefficients of the platen heating surface, the external heat exchanger (EHE...A study of the heat transfer about the heating surface of three commercial 300 MWe CFB boilers was conducted in this work. The heat transfer coefficients of the platen heating surface, the external heat exchanger (EHE) and cyclone separator were calculated according to the relative operation data at different boiler loads. Moreover, the heat transfer coefficient of the waterwall was calculated by heat balance of the hot circuit of the CFB boiler. With the boiler capacity increasing, the heat transfer coefficients of these heating surface increases, and the heat transfer coefficient of the water wall is higher than that of the platen heating surface. The heat transfer coefficient of the EHE is the highest in high boiler load, the heat transfer coefficient of the cyclone separator is the lowest. Because the fired coal is different from the design coal in No.1 boiler, the ash content of the fired coal is much lower than that of the design coal. The heat transfer coefficients which calculated with the operation data are lower than the previous design value and that is the reason why the bed temperature is rather high during the boiler operation in No.1 boiler.展开更多
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Due to randomness of wind generator＇s availability, power system planners have big concern on EEG （expected energy generation） and system reliability of power system with wind generators. This paper presents a methodology to evaluate the EEG as well as overall LOLP （loss of load probability）, which is an index for system reliability of multi-area interconnected systems with wind generators, as well as conventional fossil fuel based generating units. The proposed model is also capable of tracking the energy export incorporating the multi-state probability model for wind generator which output varies with time and season.
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supported by the National Basic Research Program of China ("973" Project) (Grant No. 2012CB215203)the National Natural Science Major Fund Project (Grant No. 51036002)
文摘With the increasing number of wind farms in power systems, the scheduling of a single wind farm needs to be improved. For this end, this paper proposes an optimal short-term load dispatch strategy for a single wind farm. Firstly, considering the large number of wind units and the high dimensionality of the scheduling solutions, we analyze the unit load characteristics, from which we extract the unit load characteristic matrix, and then classify the wind power units with the FCM fuzzy clustering algorithm. Secondly, we define the running loss indicator and action loss indicator. Based on the prediction of wind power and the load instructions, we establish a unit commitment model in wind farm, and solve the model using a combination of the fuzzy clustering algorithm and genetic algorithm, which overcomes the difficulty of the high dimensionality of the solution in the wind farm scheduling problem, to obtain the optimal scheduling strategy. Finally, through the simulation of the scheduling strategy for a 45 MW wind farm, we demonstrate the feasibility and effectiveness of the proposed strategy.
基金support from Strategic Priority Research Program of the Chinese Academy of Sciences, Grant No. XDA07030100Technology support program in the 11th Five-year Plan (2006BAA03B06)
文摘A study of the heat transfer about the heating surface of three commercial 300 MWe CFB boilers was conducted in this work. The heat transfer coefficients of the platen heating surface, the external heat exchanger (EHE) and cyclone separator were calculated according to the relative operation data at different boiler loads. Moreover, the heat transfer coefficient of the waterwall was calculated by heat balance of the hot circuit of the CFB boiler. With the boiler capacity increasing, the heat transfer coefficients of these heating surface increases, and the heat transfer coefficient of the water wall is higher than that of the platen heating surface. The heat transfer coefficient of the EHE is the highest in high boiler load, the heat transfer coefficient of the cyclone separator is the lowest. Because the fired coal is different from the design coal in No.1 boiler, the ash content of the fired coal is much lower than that of the design coal. The heat transfer coefficients which calculated with the operation data are lower than the previous design value and that is the reason why the bed temperature is rather high during the boiler operation in No.1 boiler.
