Microgrid with hybrid renewable energy sources is a promising solution where the distribution network expansion is unfeasible or not economical.Integration of renewable energy sources provides energy security,substant...Microgrid with hybrid renewable energy sources is a promising solution where the distribution network expansion is unfeasible or not economical.Integration of renewable energy sources provides energy security,substantial cost savings and reduction in greenhouse gas emissions,enabling nation to meet emission targets.Microgrid energy management is a challenging task for microgrid operator(MGO)for optimal energy utilization in microgrid with penetration of renewable energy sources,energy storage devices and demand response.In this paper,optimal energy dispatch strategy is established for grid connected and standalone microgrids integrated with photovoltaic(PV),wind turbine(WT),fuel cell(FC),micro turbine(MT),diesel generator(DG)and battery energy storage system(ESS).Techno-economic benefits are demonstrated for the hybrid power system.So far,microgrid energy management problem has been addressed with the aim of minimizing operating cost only.However,the issues of power losses and environment i.e.,emission-related objectives need to be addressed for effective energy management of microgrid system.In this paper,microgrid energy management(MGEM)is formulated as mixedinteger linear programming and a new multi-objective solution is proposed for MGEM along with demand response program.Demand response is included in the optimization problem to demonstrate it’s impact on optimal energy dispatch and techno-commercial benefits.Fuzzy interface has been developed for optimal scheduling of ESS.Simulation results are obtained for the optimal capacity of PV,WT,DG,MT,FC,converter,BES,charging/discharging scheduling,state of charge of battery,power exchange with grid,annual net present cost,cost of energy,initial cost,operational cost,fuel cost and penalty of greenhouse gases emissions.The results show that CO_(2) emissions in standalone hybrid microgrid system is reduced by 51.60%compared to traditional system with grid only.Simulation results obtained with the proposed method is compared with various evolutionary algorithms to v展开更多
Battery energy storage system(BESS)is one of the effective technologies to deal with power fluctuation and intermittence resulting from grid integration of large renewable generations.In this paper,the system configur...Battery energy storage system(BESS)is one of the effective technologies to deal with power fluctuation and intermittence resulting from grid integration of large renewable generations.In this paper,the system configuration of a China’s national renewable generation demonstration project combining a large-scale BESS with wind farm and photovoltaic(PV)power station,all coupled to a power transmission system,is introduced,and the key technologies including optimal control and management as well as operational status of this BESS are presented.Additionally,the technical benefits of such a large-scale BESS in dealing with power fluctuation and intermittence issues resulting from grid connection of large-scale renewable generation,and for improvement of operation characteristics of transmission grid,are discussed with relevant case studies.展开更多
The distribution and storage of soil organic carbon (SOC) based on a long-term experiment with various tillage systems were studied in a paddy soil derived from purple soil in Chongqing, China. Organic carbon storage ...The distribution and storage of soil organic carbon (SOC) based on a long-term experiment with various tillage systems were studied in a paddy soil derived from purple soil in Chongqing, China. Organic carbon storage in the 0-20 and 0-40 cm soil layers under different tillage systems were in an order: ridge tillage with rice-rape rotation (RT-rr) > conventional tillage with rice only (CT-r) > ridge tillage with rice only (RT-r) > conventional tillage with rice-rape rotation (CT-rr). The RT-rr system had significantly higher levels of soil organic carbon in the 0-40 cm topsoil, while the proportion of the total remaining organic carbon in the total soil organic carbon in the 0-10 cm layer was greatest in the RT-rr system. This was the reason why the RT-rr system enhanced soil organic carbon storage. These showed that tillage system type was crucial for carbon storage. Carbon levels in soil humus and crop-yield results showed that the RT-rr system enhanced soil fertility and crop productivity. Adoption of this tillage system would be beneficial both for environmental protection and economic development.展开更多
文摘Microgrid with hybrid renewable energy sources is a promising solution where the distribution network expansion is unfeasible or not economical.Integration of renewable energy sources provides energy security,substantial cost savings and reduction in greenhouse gas emissions,enabling nation to meet emission targets.Microgrid energy management is a challenging task for microgrid operator(MGO)for optimal energy utilization in microgrid with penetration of renewable energy sources,energy storage devices and demand response.In this paper,optimal energy dispatch strategy is established for grid connected and standalone microgrids integrated with photovoltaic(PV),wind turbine(WT),fuel cell(FC),micro turbine(MT),diesel generator(DG)and battery energy storage system(ESS).Techno-economic benefits are demonstrated for the hybrid power system.So far,microgrid energy management problem has been addressed with the aim of minimizing operating cost only.However,the issues of power losses and environment i.e.,emission-related objectives need to be addressed for effective energy management of microgrid system.In this paper,microgrid energy management(MGEM)is formulated as mixedinteger linear programming and a new multi-objective solution is proposed for MGEM along with demand response program.Demand response is included in the optimization problem to demonstrate it’s impact on optimal energy dispatch and techno-commercial benefits.Fuzzy interface has been developed for optimal scheduling of ESS.Simulation results are obtained for the optimal capacity of PV,WT,DG,MT,FC,converter,BES,charging/discharging scheduling,state of charge of battery,power exchange with grid,annual net present cost,cost of energy,initial cost,operational cost,fuel cost and penalty of greenhouse gases emissions.The results show that CO_(2) emissions in standalone hybrid microgrid system is reduced by 51.60%compared to traditional system with grid only.Simulation results obtained with the proposed method is compared with various evolutionary algorithms to v
基金supported by National Natural Science Foundation of China(No.51107126 and No.512111046)the Key Projects in National Science and Technology Pillar Program(No.2011BAA07B07)+1 种基金the Beiing Nova Program(No.Z141101001814094)the Science and Technology Foundation of State Grid Corporation of China(No.DG71-14-032)
文摘Battery energy storage system(BESS)is one of the effective technologies to deal with power fluctuation and intermittence resulting from grid integration of large renewable generations.In this paper,the system configuration of a China’s national renewable generation demonstration project combining a large-scale BESS with wind farm and photovoltaic(PV)power station,all coupled to a power transmission system,is introduced,and the key technologies including optimal control and management as well as operational status of this BESS are presented.Additionally,the technical benefits of such a large-scale BESS in dealing with power fluctuation and intermittence issues resulting from grid connection of large-scale renewable generation,and for improvement of operation characteristics of transmission grid,are discussed with relevant case studies.
基金Project supported by the National Natural Science Foundation of China (No. 40231016).
文摘The distribution and storage of soil organic carbon (SOC) based on a long-term experiment with various tillage systems were studied in a paddy soil derived from purple soil in Chongqing, China. Organic carbon storage in the 0-20 and 0-40 cm soil layers under different tillage systems were in an order: ridge tillage with rice-rape rotation (RT-rr) > conventional tillage with rice only (CT-r) > ridge tillage with rice only (RT-r) > conventional tillage with rice-rape rotation (CT-rr). The RT-rr system had significantly higher levels of soil organic carbon in the 0-40 cm topsoil, while the proportion of the total remaining organic carbon in the total soil organic carbon in the 0-10 cm layer was greatest in the RT-rr system. This was the reason why the RT-rr system enhanced soil organic carbon storage. These showed that tillage system type was crucial for carbon storage. Carbon levels in soil humus and crop-yield results showed that the RT-rr system enhanced soil fertility and crop productivity. Adoption of this tillage system would be beneficial both for environmental protection and economic development.
