This paper presents a method for optimal sizing of an off-grid hybrid microgrid (MG) system in order to achieve a certain load demand. The hybrid MG is made of a solar photovoltaic (PV) system, wind turbine (TW) and e...This paper presents a method for optimal sizing of an off-grid hybrid microgrid (MG) system in order to achieve a certain load demand. The hybrid MG is made of a solar photovoltaic (PV) system, wind turbine (TW) and energy storage system (ESS). The reliability of the MG system is modeled based on the loss of power supply probability (SPSP). For optimization, an enhanced Genetic Algorithm (GA) is used to minimize the total cost of the system over a 20-year period, while satisfying some reliability and operation constraints. A case study addressing optimal sizing of an off-grid hybrid microgrid in Nigeria is discussed. The result is compared with results obtained from the Brute Force and standard GA methods.展开更多
100-W class power storage systems were developed, which comprised spherical Si solar cells, a maximum power point tracking charge control-ler, a lithium-ion battery, and one of two different types of direct current (D...100-W class power storage systems were developed, which comprised spherical Si solar cells, a maximum power point tracking charge control-ler, a lithium-ion battery, and one of two different types of direct current (DC)-alter- nating current (AC) converters. One inverter used SiC met-al-oxide-semicon-ductor field-effect transistors (MOSFETs) as switching devices while the other used Si MOSFETs. In these 100-W class inverters, the ON resistance was considered to have little influence on the efficiency. Nevertheless, the SiC-based inverter exhibited an approximately 3% higher DC-AC conversion efficiency than the Si-based inverter. Power loss analysis indicated that the higher efficiency resulted predominantly from lower switching and reverse recovery losses in the SiC MOSFETs compared with in the Si MOSFETs.展开更多
Chinese government has been devoting itself to the development of renewable energy sources. This paper describes the history, achievement and future trends of photovoltaie technology, and suggestions axe proposed for ...Chinese government has been devoting itself to the development of renewable energy sources. This paper describes the history, achievement and future trends of photovoltaie technology, and suggestions axe proposed for strengthening the research and development （R＆D） ability of China.展开更多
The concept of utilizing microgrids(MGs)to convert buildings into prosumers is gaining massive popularity because of its economic and environmental benefits.These pro-sumer buildings consist of renewable energy source...The concept of utilizing microgrids(MGs)to convert buildings into prosumers is gaining massive popularity because of its economic and environmental benefits.These pro-sumer buildings consist of renewable energy sources and usually install battery energy storage systems(BESSs)to deal with the uncertain nature of renewable energy sources.However,because of the high capital investment of BESS and the limitation of available energy,there is a need for an effective energy management strategy for prosumer buildings that maximizes the profit of building owner and increases the operating life span of BESS.In this regard,this paper proposes an improved energy management strategy(IEMS)for the prosumer building to minimize the operating cost of MG and degradation factor of BESS.Moreover,to estimate the practical operating life span of BESS,this paper utilizes a non-linear battery degradation model.In addition,a flexible load shifting(FLS)scheme is also developed and integrated into the proposed strategy to further improve its performance.The proposed strategy is tested for the real-time annual data of a grid-tied solar photovoltaic(PV)and BESS-powered AC-DC hybrid MG installed at a commercial building.Moreover,the scenario reduction technique is used to handle the uncertainty associated with generation and load demand.To validate the performance of the proposed strategy,the results of IEMS are compared with the well-established energy management strategies.The simulation results verify that the proposed strategy substantially increases the profit of the building owner and operating life span of BESS.Moreover,FLS enhances the performance of IEMS by further improving the financial profit of MG owner and the life span of BESS,thus making the operation of prosumer building more economical and efficient.展开更多
利用恒压频闪式I-V曲线测试仪研究分析温度和光强对聚光硅电池特性参数的影响。研究发现,聚光硅电池开路电压V_(oc) 的温度系数随聚光比升高不断降低,从1倍聚光比的-1.97 m V/K降低到30倍聚光比的-1.71 m V/K,和其理论计算值吻合较好;...利用恒压频闪式I-V曲线测试仪研究分析温度和光强对聚光硅电池特性参数的影响。研究发现,聚光硅电池开路电压V_(oc) 的温度系数随聚光比升高不断降低,从1倍聚光比的-1.97 m V/K降低到30倍聚光比的-1.71 m V/K,和其理论计算值吻合较好;和普通单晶硅电池开路电压V_(oc) 温度系数相比,该电池的要小,上述说明聚光硅电池在聚光下工作有利于其在较高温度下操作。聚光硅电池填充因子和效率均随温度升高而降低;由于串联电阻影响,该电池效率随聚光比的增大先增后减,适合在小于20倍聚光比下的系统中工作。可进一步优化该电池金属栅线覆盖率和阻值引起的功率损失以提高其适合应用的聚光比。展开更多
文摘This paper presents a method for optimal sizing of an off-grid hybrid microgrid (MG) system in order to achieve a certain load demand. The hybrid MG is made of a solar photovoltaic (PV) system, wind turbine (TW) and energy storage system (ESS). The reliability of the MG system is modeled based on the loss of power supply probability (SPSP). For optimization, an enhanced Genetic Algorithm (GA) is used to minimize the total cost of the system over a 20-year period, while satisfying some reliability and operation constraints. A case study addressing optimal sizing of an off-grid hybrid microgrid in Nigeria is discussed. The result is compared with results obtained from the Brute Force and standard GA methods.
文摘100-W class power storage systems were developed, which comprised spherical Si solar cells, a maximum power point tracking charge control-ler, a lithium-ion battery, and one of two different types of direct current (DC)-alter- nating current (AC) converters. One inverter used SiC met-al-oxide-semicon-ductor field-effect transistors (MOSFETs) as switching devices while the other used Si MOSFETs. In these 100-W class inverters, the ON resistance was considered to have little influence on the efficiency. Nevertheless, the SiC-based inverter exhibited an approximately 3% higher DC-AC conversion efficiency than the Si-based inverter. Power loss analysis indicated that the higher efficiency resulted predominantly from lower switching and reverse recovery losses in the SiC MOSFETs compared with in the Si MOSFETs.
文摘Chinese government has been devoting itself to the development of renewable energy sources. This paper describes the history, achievement and future trends of photovoltaie technology, and suggestions axe proposed for strengthening the research and development （R＆D） ability of China.
基金supported in part by the Department of Science and Technology,Government of India,New Delhi,India“Internet of Things(IoT)Research of Interdisciplinary Cyber-Physical Systems Program”(No.DST/ICPS/CLUSTER/IoT/2018/General)。
文摘The concept of utilizing microgrids(MGs)to convert buildings into prosumers is gaining massive popularity because of its economic and environmental benefits.These pro-sumer buildings consist of renewable energy sources and usually install battery energy storage systems(BESSs)to deal with the uncertain nature of renewable energy sources.However,because of the high capital investment of BESS and the limitation of available energy,there is a need for an effective energy management strategy for prosumer buildings that maximizes the profit of building owner and increases the operating life span of BESS.In this regard,this paper proposes an improved energy management strategy(IEMS)for the prosumer building to minimize the operating cost of MG and degradation factor of BESS.Moreover,to estimate the practical operating life span of BESS,this paper utilizes a non-linear battery degradation model.In addition,a flexible load shifting(FLS)scheme is also developed and integrated into the proposed strategy to further improve its performance.The proposed strategy is tested for the real-time annual data of a grid-tied solar photovoltaic(PV)and BESS-powered AC-DC hybrid MG installed at a commercial building.Moreover,the scenario reduction technique is used to handle the uncertainty associated with generation and load demand.To validate the performance of the proposed strategy,the results of IEMS are compared with the well-established energy management strategies.The simulation results verify that the proposed strategy substantially increases the profit of the building owner and operating life span of BESS.Moreover,FLS enhances the performance of IEMS by further improving the financial profit of MG owner and the life span of BESS,thus making the operation of prosumer building more economical and efficient.
文摘利用恒压频闪式I-V曲线测试仪研究分析温度和光强对聚光硅电池特性参数的影响。研究发现,聚光硅电池开路电压V_(oc) 的温度系数随聚光比升高不断降低,从1倍聚光比的-1.97 m V/K降低到30倍聚光比的-1.71 m V/K,和其理论计算值吻合较好;和普通单晶硅电池开路电压V_(oc) 温度系数相比,该电池的要小,上述说明聚光硅电池在聚光下工作有利于其在较高温度下操作。聚光硅电池填充因子和效率均随温度升高而降低;由于串联电阻影响,该电池效率随聚光比的增大先增后减,适合在小于20倍聚光比下的系统中工作。可进一步优化该电池金属栅线覆盖率和阻值引起的功率损失以提高其适合应用的聚光比。
