[Objective] The aim was to study the relation between solar radiation distribution and meteorological elements in Guangxi. [Method] Based on the observed data of solar radiation in Guangxi from 1995 to 2009, the total...[Objective] The aim was to study the relation between solar radiation distribution and meteorological elements in Guangxi. [Method] Based on the observed data of solar radiation in Guangxi from 1995 to 2009, the total radiation, solar distribution and interannual changes in Guangxi were analyzed. By dint of observed data in Nanning station, the annual, seasonal and monthly changes of net radiation in Nanning and the linear relation between total radiation, solar distribution characteristics and interannual changes were discussed. [Result] The global radiation of surface solar radiation in the low latitude was higher tan the high latitude, as Beihai>Nanning>Guilin. The solar radiation changes and the seasonal changes in different places varied, as summer>autumn>spring>winter. The total radiation and solar radiation hours were consistent. The total solar radiation and the low cloud was in negative relation, but was in positive relation with sunny weather. The total solar radiation was in positive relation with ground temperature, except in winter. [Conclusion] The study provided effective theoretical basis and data reference to the study of climate and development of solar energy.展开更多
针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,...针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,结果表明:电弧电流的电磁辐射特征频段为20~30 MHz,该特征频段不会受到中性点接地方式、电弧接地介质与线路结构参数的显著影响,且特征频段内辐射信号在传播过程中衰减较慢。在此基础上,设计一种小型化三角形单极子–环形组合平面天线,工作频率为20~500 MHz。利用自制天线开展小型电弧故障定位实验,为后续配网电弧故障定位的应用研究提供基础。展开更多
Solar energy is clean and renewable energy that plays an important role in mitigating impacts of environmental problems and climate change.Solar radiation received on the earth's surface determines the efficiency ...Solar energy is clean and renewable energy that plays an important role in mitigating impacts of environmental problems and climate change.Solar radiation received on the earth's surface determines the efficiency of power generation and the location and layout of photovoltaic arrays.In this paper,the average daily solar radiation of 77 stations in China from 1957 to 2016 was analyzed in terms of spatial and temporal characteristics.The results indicate that Xinjiang,the Qinghai-Tibet Plateau,North,Central and East China show a decreasing trend with an average of 2.54×10^(−3)MJ/(m^(2)⋅10a),while Northwest and Northeast China are basically stabilized,and Southwest China shows a clear increasing trend with an average increase of 1.79×10^(−3)MJ/(m^(2)⋅10a).The average daily solar radiation in summer and winter in China from 1957 to 2016 was 18.74 MJ/m^(2)and 9.09 MJ/m^(2),respectively.Except for spring in Northwest,East and South China,and summer in northeast China,the average daily solar radiation in all other regions show a downward trend.A critical point for the change is 1983 in the average daily solar radiation.Meanwhile,large-scale(25−30 years)oscillation changes are more obvious,while small-scale(5−10 years)changes are stable and have a global scope.The average daily solar radiation shows an increasing-decreasing gradient from west to east,which can be divided into three areas west of 80°E,80°E−100°E and east of 100°E.The average daily solar radiation was 2.07 MJ/m^(2)in the 1980s,and that in 1990s lower than that in the 1960s and the 1970s.The average daily solar radiation has rebounded in the 21st century,but overall it is still lower than the average daily solar radiation from 1957 to 2016(13.87 MJ/m^(2)).展开更多
The transparent envelope structure has huge energy-saving potential, which is the key point to reduce building energy consumption and improve the thermal building environment. The solar radiation transmitted through t...The transparent envelope structure has huge energy-saving potential, which is the key point to reduce building energy consumption and improve the thermal building environment. The solar radiation transmitted through the transparent envelope structure(transmitted solar radiation) is reflected, scattered and absorbed by the indoor surface, which has a significant impact on the heat gain of the building. In this paper, firstly, the diffuse radiation received by different depths of various indoor surfaces is measured by experimental tests, and the distribution function of transmitted diffuse solar radiation(TDSR) on the indoor surface is established. Secondly, the diffuse solar radiation received by the indoor and outdoor surfaces in different seasons is continuously monitored;the variation of TDSR with time is analyzed, and the distribution function of TDSR on indoor surface with time is proposed. Finally, based on the temporal and spatial distribution characteristics of diffuse radiation under different weather conditions, the variation of TDSR with the weather is studied, and the distribution function of TDSR on the indoor surface with weather changes is established. The distribution function of the TDSR on the indoor surface under different depths, time and weather conditions obtained in this study can supplement and improve the theory of building heat gain and load, and help accurate simulation of building energy consumption.展开更多
文摘[Objective] The aim was to study the relation between solar radiation distribution and meteorological elements in Guangxi. [Method] Based on the observed data of solar radiation in Guangxi from 1995 to 2009, the total radiation, solar distribution and interannual changes in Guangxi were analyzed. By dint of observed data in Nanning station, the annual, seasonal and monthly changes of net radiation in Nanning and the linear relation between total radiation, solar distribution characteristics and interannual changes were discussed. [Result] The global radiation of surface solar radiation in the low latitude was higher tan the high latitude, as Beihai>Nanning>Guilin. The solar radiation changes and the seasonal changes in different places varied, as summer>autumn>spring>winter. The total radiation and solar radiation hours were consistent. The total solar radiation and the low cloud was in negative relation, but was in positive relation with sunny weather. The total solar radiation was in positive relation with ground temperature, except in winter. [Conclusion] The study provided effective theoretical basis and data reference to the study of climate and development of solar energy.
文摘针对架空配电线路电弧接地故障点定位难题,该文研究架空配电线路故障电弧的电磁辐射特性,探索基于电磁辐射信号的电弧故障定位方法的可行性。通过10 k V配网真型故障模拟试验平台,分析接地电弧电磁辐射的时域与频域特性及传播衰减规律,结果表明:电弧电流的电磁辐射特征频段为20~30 MHz,该特征频段不会受到中性点接地方式、电弧接地介质与线路结构参数的显著影响,且特征频段内辐射信号在传播过程中衰减较慢。在此基础上,设计一种小型化三角形单极子–环形组合平面天线,工作频率为20~500 MHz。利用自制天线开展小型电弧故障定位实验,为后续配网电弧故障定位的应用研究提供基础。
基金support provided by the National Key R&D Program of China(2018YFB1502800).
文摘Solar energy is clean and renewable energy that plays an important role in mitigating impacts of environmental problems and climate change.Solar radiation received on the earth's surface determines the efficiency of power generation and the location and layout of photovoltaic arrays.In this paper,the average daily solar radiation of 77 stations in China from 1957 to 2016 was analyzed in terms of spatial and temporal characteristics.The results indicate that Xinjiang,the Qinghai-Tibet Plateau,North,Central and East China show a decreasing trend with an average of 2.54×10^(−3)MJ/(m^(2)⋅10a),while Northwest and Northeast China are basically stabilized,and Southwest China shows a clear increasing trend with an average increase of 1.79×10^(−3)MJ/(m^(2)⋅10a).The average daily solar radiation in summer and winter in China from 1957 to 2016 was 18.74 MJ/m^(2)and 9.09 MJ/m^(2),respectively.Except for spring in Northwest,East and South China,and summer in northeast China,the average daily solar radiation in all other regions show a downward trend.A critical point for the change is 1983 in the average daily solar radiation.Meanwhile,large-scale(25−30 years)oscillation changes are more obvious,while small-scale(5−10 years)changes are stable and have a global scope.The average daily solar radiation shows an increasing-decreasing gradient from west to east,which can be divided into three areas west of 80°E,80°E−100°E and east of 100°E.The average daily solar radiation was 2.07 MJ/m^(2)in the 1980s,and that in 1990s lower than that in the 1960s and the 1970s.The average daily solar radiation has rebounded in the 21st century,but overall it is still lower than the average daily solar radiation from 1957 to 2016(13.87 MJ/m^(2)).
基金support of the National Natural Science Foundation of China(Grant No52178083)Open Project of Key Laboratory of Solar Energy Utilization&Energy Saving Technology of Zhejiang Province(Grant No.JSYJY-KJWZ-2021-011)。
文摘The transparent envelope structure has huge energy-saving potential, which is the key point to reduce building energy consumption and improve the thermal building environment. The solar radiation transmitted through the transparent envelope structure(transmitted solar radiation) is reflected, scattered and absorbed by the indoor surface, which has a significant impact on the heat gain of the building. In this paper, firstly, the diffuse radiation received by different depths of various indoor surfaces is measured by experimental tests, and the distribution function of transmitted diffuse solar radiation(TDSR) on the indoor surface is established. Secondly, the diffuse solar radiation received by the indoor and outdoor surfaces in different seasons is continuously monitored;the variation of TDSR with time is analyzed, and the distribution function of TDSR on indoor surface with time is proposed. Finally, based on the temporal and spatial distribution characteristics of diffuse radiation under different weather conditions, the variation of TDSR with the weather is studied, and the distribution function of TDSR on the indoor surface with weather changes is established. The distribution function of the TDSR on the indoor surface under different depths, time and weather conditions obtained in this study can supplement and improve the theory of building heat gain and load, and help accurate simulation of building energy consumption.
