In order to control the output power of a switched reluctance generator(SRG)at a constant speed,the output power of SRG is theoretically analyzed by using freewheeling control.First,through a theoretical analysis,a fi...In order to control the output power of a switched reluctance generator(SRG)at a constant speed,the output power of SRG is theoretically analyzed by using freewheeling control.First,through a theoretical analysis,a finite element simulation and an experiment,it was verified that the output power of SRG cannot be improved by using freewheeling control with a single pulse control method(SPCM).Then,the maximum output power can be obtained by optimizing the turn off angles of SPCM at a constant speed,and at the same time,the formula of the optimal turn-off angle was presented,which meets the criterion for the output power maximization.Finally,numerical simulation and experimental results demonstrated the validity of the theoretical analysis.展开更多
This paper analyses the greenhouse gas (GHG) emission along the value chains of two strategic commodities in West Africa (rice and maize) in four pilot countries: Ghana, Senegal Benin and Cote D’Ivoire. The Value Cha...This paper analyses the greenhouse gas (GHG) emission along the value chains of two strategic commodities in West Africa (rice and maize) in four pilot countries: Ghana, Senegal Benin and Cote D’Ivoire. The Value Chains Analysis and Greenhouse model used in this study, provides insight into the relationship between output maximization and GHG emissions to help define optimal intervention approaches that minimize emissions while maximizing the potential yield, hence boost food security. It highlights intervention measures for improvement of production and productivity along with the identification of mitigation measures to reduce GHG emissions. It also revealed that the largest GHG emission factor from maize farming in the selected countries is from the application of nitrogen fertilizers (NO2), and for rice farming, depending on the systems, e.g. rain fed, irrigated or multiple aeration, the emission is mostly due to anaerobic decomposition of methane (CH4) which increases with flooding practice.展开更多
文摘In order to control the output power of a switched reluctance generator(SRG)at a constant speed,the output power of SRG is theoretically analyzed by using freewheeling control.First,through a theoretical analysis,a finite element simulation and an experiment,it was verified that the output power of SRG cannot be improved by using freewheeling control with a single pulse control method(SPCM).Then,the maximum output power can be obtained by optimizing the turn off angles of SPCM at a constant speed,and at the same time,the formula of the optimal turn-off angle was presented,which meets the criterion for the output power maximization.Finally,numerical simulation and experimental results demonstrated the validity of the theoretical analysis.
文摘This paper analyses the greenhouse gas (GHG) emission along the value chains of two strategic commodities in West Africa (rice and maize) in four pilot countries: Ghana, Senegal Benin and Cote D’Ivoire. The Value Chains Analysis and Greenhouse model used in this study, provides insight into the relationship between output maximization and GHG emissions to help define optimal intervention approaches that minimize emissions while maximizing the potential yield, hence boost food security. It highlights intervention measures for improvement of production and productivity along with the identification of mitigation measures to reduce GHG emissions. It also revealed that the largest GHG emission factor from maize farming in the selected countries is from the application of nitrogen fertilizers (NO2), and for rice farming, depending on the systems, e.g. rain fed, irrigated or multiple aeration, the emission is mostly due to anaerobic decomposition of methane (CH4) which increases with flooding practice.
