Because of the randomness of wind power and photovoltaic(PV)output of new energy bases,the problem of peak regulation capability and voltage stability of ultra-high voltage direct current(UHVDC)transmission lines,we p...Because of the randomness of wind power and photovoltaic(PV)output of new energy bases,the problem of peak regulation capability and voltage stability of ultra-high voltage direct current(UHVDC)transmission lines,we proposed an optimum allocation method of installed capacity of the solar-thermal power station based on chance constrained programming in this work.Firstly,we established the uncertainty model of wind power and PV based on the chance constrained planning theory.Then we used the K-medoids clusteringmethod to cluster the scenarios considering the actual operation scenarios throughout the year.Secondly,we established the optimal configuration model based on the objective function of the strongest transient voltage stability and the lowest overall cost of operation.Finally,by quantitative analysis of actual wind power and photovoltaic new energy base,this work verified the feasibility of the proposed method.As a result of the simulations,we found that using the optimal configuration method of solar-thermal power stations could ensure an accurate allocation of installed capacity.When the installed capacity of the solar-thermal power station is 1×106 kW,the transient voltage recovery index(TVRI)is 0.359,which has a strong voltage support capacity for the system.Based on the results of this work,the optimal configuration of the installed capacity of the solar-thermal power plant can improve peak shaving performance,transient voltage support capability,and new energy consumption while satisfying the Direct Current(DC)outgoing transmission premise.展开更多
At present the mechanical model of the interac- tion between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine (TBM) on-site data. This is not in line...At present the mechanical model of the interac- tion between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine (TBM) on-site data. This is not in line with the actual rock-breaking movement of the disc cutter and impedes to some extent the research on the rock-breaking mechanism, wear mechanism and design theory. Therefore, our study focuses on the interaction between the slantingly installed disc cutter and rock, developing a model in accordance with the actual rock-breaking movement. Displacement equations are established through an analysis of the velocity vector at the rock-breaking point of the disc cutter blade; the func- tional relationship between the displacement parameters at the rock-breaking point and its rectangular coordinates is established through an analysis of micro-displacement vectors at the rock-breaking point, thus leading to the geometric equations of rock deformation caused by the slantingly installed disc cutter. Considering the basically linear relationship between the cutting force of disc cutters and the rock deformation before and after the leap break of rock, we express the constitutive relations of rock deformation as generalized Hooke's law and analyze the effect of the slanting installa- tion angle of disc cutters on the rock-breaking force. This will, as we hope, make groundbreaking contributions to the development of the design theory and installation practice of TBM.展开更多
This paper proposes a novel method to calculate the best installed capacity of pumped storage power station. First, we choose the day with maximum load as the typical day for every month and simulate the system runnin...This paper proposes a novel method to calculate the best installed capacity of pumped storage power station. First, we choose the day with maximum load as the typical day for every month and simulate the system running in two cases of whether the pumped storage power station is put into operation. The difference of the total coal consumption between the two cases is the peak load shifting benefit. Furthermore, we build load model and power generation model to calculate the benefit of emergency use and frequency modulation, which are the major projects of dynamic benefits. At last, on the premise of ensuring the system requirements, the developed method employs the maximum benefit of the unit capacity as the objective function to get the best installed capacity of pumped storage power station by simulations. Tests on a provincial power grid have shown that the developed method which combines of load characteristics, electric structure and other factors can get the best installed capacity of pumped storage power station easily and has a certain guiding significance for the planning and construction of the pumped storage power station.展开更多
At present, disc cutters of a full face rock tunnel boring machine are mostly mounted in the traditional way. Practical use in engineering projects reveals that this installation method not only heavily affects the op...At present, disc cutters of a full face rock tunnel boring machine are mostly mounted in the traditional way. Practical use in engineering projects reveals that this installation method not only heavily affects the operation life of disc cutters, but also increases the energy consumption of a full face rock tunnel boring machine. To straighten out this issue, therefore, a rock-breaking model is developed for disc cutters' movement after the research on the rock breaking of forward-slanting disc cutters. Equations of its displacement are established based on the analysis of velocity vector of a disc cutter's rock-breaking point. The functional relations then are brought forward between the displacement parameters of a rock-breaking point and its coordinate through the analysis of micro displacement of a rock-breaking point. Thus, the geometric equations of rock deformation are derived for the forward-slanting installation of disc cutters. With a linear relationship remaining between the acting force and its deformation either before or after the leap breaking, the constitutive relation of rock deformation can be expressed in the form of generalized Hooke law, hence the comparative analysis of the variation in the resistance of rock to the disc cutters mounted in the forward-slanting way with that in the traditional way. It is discovered that with the same penetration, strain of the rock in contact with forwardslanting disc cutters is apparently on the decline, in otherwords, the resistance of rock to disc cutters is reduced. Thus wear of disc cutters resulted from friction is lowered and energy consumption is correspondingly decreased. It will be useful for the development of installation and design theory of disc cutters, and significant for the breakthrough in the design of full face rock tunnel boring machine.展开更多
There are two kinds of generating equipment in a firmly con-nected power network,one is water power plants(shortenedas“water power”,below),the other is thermal power plants(includingcoal-fired,oil-fired and nuclear ...There are two kinds of generating equipment in a firmly con-nected power network,one is water power plants(shortenedas“water power”,below),the other is thermal power plants(includingcoal-fired,oil-fired and nuclear power plants,but the analysis in thisarticle is based mainly on coal-fired power generation.And they willbe shortened as“thermal power”below).As far as power output isconcerned,when the share of water power installed capacity展开更多
China's installed capacity of storage batteries to power electric vehicles saw a year-on-year increase of 9.2 percent in 2019,industry data has shown.The rise came amid the country's stepped-up efforts for gre...China's installed capacity of storage batteries to power electric vehicles saw a year-on-year increase of 9.2 percent in 2019,industry data has shown.The rise came amid the country's stepped-up efforts for greener growth,including the use of new energy vehicles (NEV).In 2019,the installed capacity of storage batteries reached 62.2 gigawatt hours,according to data from the China automotive power battery industry innovation alliance.展开更多
According to the statistics of energy industry,China's installed capacity of renewable energy power reached 1.002 billion kW in 2021,accounting for 43.5%of the country's total installed capacity,which was 10.2...According to the statistics of energy industry,China's installed capacity of renewable energy power reached 1.002 billion kW in 2021,accounting for 43.5%of the country's total installed capacity,which was 10.2 percentage higher than that of 2015.In the total renewable energy power,the installed capacities of hydropower,wind power,solar power and biomass power reached 385 million kW,299 million kW,282 million kW and 35.34 million kW,respectively,continuing to be the number one in the world.展开更多
The journalist learned from the "National Gas Security Working Conference" held recently that the coal seam gas power generation has been rapidly developed in recent years.As of July 2009,within the SGCC'...The journalist learned from the "National Gas Security Working Conference" held recently that the coal seam gas power generation has been rapidly developed in recent years.As of July 2009,within the SGCC's business area,the power generation展开更多
A new dynamically installed plate anchor, the Flying Wing Anchor~?, has been developed as a sustainable anchor concept for deep-water offshore wind turbines. The anchor is firstly installed by free-fall penetration an...A new dynamically installed plate anchor, the Flying Wing Anchor~?, has been developed as a sustainable anchor concept for deep-water offshore wind turbines. The anchor is firstly installed by free-fall penetration and then followed by drag embedment. If the anchor is subjected to environmental loads, it dives deeper to mobilize a higher capacity. This study presents a series of free-fall penetration tests with model anchors in different weights to assess the anchor behavior during the free-fall penetration performance in one-layer soil with a constant shear strength profile. Anchor velocities and embedment depths were measured by a magnetometer. An energy-based model and a force-based model were calibrated against the test results of model anchors with different weights. Based on the calibrated force-based model, a series of design charts were developed to estimate the embedment depth of anchors in different sizes and with different impact velocities in various marine clays. The framework to plot design charts presented herein can be potentially applied to other dynamically installed anchors to predict embedment depth in engineering practice.展开更多
Solar Photovoltaic (PV) can be considered as one of the most reliable and promising renewable systems. This is of great importance for developing countries like Nigeria especially in the rural communities where there ...Solar Photovoltaic (PV) can be considered as one of the most reliable and promising renewable systems. This is of great importance for developing countries like Nigeria especially in the rural communities where there is little or no access to electricity. The use of solar energy will no doubt contribute to the improvement of the living conditions of these villagers. Solar PV systems have been installed in some villages in Nigeria but unfortunately, the expected benefits from using these systems have been jeopardized. The objective of this work is to embark on performance assessments of in- stalled Solar PV system in Oke-Agunla, Akure local government of Ondo State in Nigeria. Visits were conducted to the village;equipments on ground were examined while the people were interviewed. Both functional and non-functional facilities were traced to their manufacturers using the identification data on them and rated to ensure their efficiencies. Energy demands were also prorated, and observed the need to improve on the present energy supplied. Results of the assessments shows that PV facilities used were inadequate, trained technicians were not available giving room for quacks working on the facilities occasionally resulted in further complications and poor facilities maintenance. The assessment result shows that just 14.52% of the 4.5 kW installed solar PV was utilized due to significant malfunctioning and deterioration in performance. It can be concluded from this study that the installed solar PV systems was inefficient as a result of poor maintenance, lack of technical know-how and inability of the project contractors or managers to take these factors into consideration while embarking on the solar PV installations.展开更多
In the first half of this year,the installed capacity of photovoltaic power generation was 78.42 GW(one GW is equal to one million kilowatts),an increase of over 150%year-on-year,close to the installed capacity data o...In the first half of this year,the installed capacity of photovoltaic power generation was 78.42 GW(one GW is equal to one million kilowatts),an increase of over 150%year-on-year,close to the installed capacity data of last year(87.41 GW),accounting for 56%of the installed capacity of new power sources in the first half of this year.By the end of June,the cumulative installed capacity of photovoltaic in China was about 470 million kilowatts,and photovoltaic has become the second largest installed power source in China,second only to coal-fired power.展开更多
The positive figures of last year confirm the strength,resilience,and prospects of the Chinese economy.CHINA’S government work report delivered to the 2024“Two Sessions”in early March released some important statis...The positive figures of last year confirm the strength,resilience,and prospects of the Chinese economy.CHINA’S government work report delivered to the 2024“Two Sessions”in early March released some important statistics.The GDP surpassed RMB 126 trillion,an increase of 5.2 percent.A total of 12.44 million urban jobs were added,and the average surveyed urban unemployment rate stood at 5.2 percent by average.The consumer price index(CPI)rose by 0.2 percent.The production and sales of new-energy vehicles accounted for over 60 percent of the world’s total.Grain output hit a record high of 695 million tonnes.The installed renewable energy capacity surpassed its thermal power for the first time in Chinese history,accounting for over half of newly installed renewable energy capacity worldwide.The per capita disposable income of residents also rose by 6.1 percent nationwide.展开更多
Avivid three-dimensional rendering of a bridge appeared on the intelligent monitor and evaluation platform at Beijing Yunlu Technology Co.,Ltd.,pointing to key factors of bridge health.Real-time status,events,transpor...Avivid three-dimensional rendering of a bridge appeared on the intelligent monitor and evaluation platform at Beijing Yunlu Technology Co.,Ltd.,pointing to key factors of bridge health.Real-time status,events,transportation navigation,and traffic conditions were all tracked on the screen.Numerous sensors installed on bridge track every minor dynamic change on the bridge surface and perform digital analysis.展开更多
"In 2023,China's photovoltaic industry continued to maintain a rapid development momentum,with an additional installed capacity of more than 216 GW,accounting for more than half of the global total.The cumula..."In 2023,China's photovoltaic industry continued to maintain a rapid development momentum,with an additional installed capacity of more than 216 GW,accounting for more than half of the global total.The cumulative installed capacity is close to 610 GW,which helps the installed capacity of renewable energy surpass that of thermal power historically.In 2023,the output value of the domestic photovoltaic manufacturing industry exceeded RMB1.75 trillion,a year-on-year increase of 17.1%,and the output of the four main industrial chains of polysilicon.展开更多
Here are some of the achievements China made in 2023:GDP exceeded 126 trillion yuan($17.43 trillion)with a growth of 5.2 percent;12.44 million new urban jobs were created;average surveyed unemployment rate in urban ar...Here are some of the achievements China made in 2023:GDP exceeded 126 trillion yuan($17.43 trillion)with a growth of 5.2 percent;12.44 million new urban jobs were created;average surveyed unemployment rate in urban areas was 5.2 percent;consumer price index increased by 0.2 percent;new energy vehicle production and sales accounted for more than 60 percent of the global share;grain output reached a record high of 695 billion kg;installed renewable energy capacity surpassed thermal power capacity for the first time in history,and China accounted for over half of newly installed renewable energy capacity worldwide;per-capita disposable income of residents increased by 6.1 percent…展开更多
基金funded by Major Science and Technology Projects in Gansu Province(19ZD2GA003).
文摘Because of the randomness of wind power and photovoltaic(PV)output of new energy bases,the problem of peak regulation capability and voltage stability of ultra-high voltage direct current(UHVDC)transmission lines,we proposed an optimum allocation method of installed capacity of the solar-thermal power station based on chance constrained programming in this work.Firstly,we established the uncertainty model of wind power and PV based on the chance constrained planning theory.Then we used the K-medoids clusteringmethod to cluster the scenarios considering the actual operation scenarios throughout the year.Secondly,we established the optimal configuration model based on the objective function of the strongest transient voltage stability and the lowest overall cost of operation.Finally,by quantitative analysis of actual wind power and photovoltaic new energy base,this work verified the feasibility of the proposed method.As a result of the simulations,we found that using the optimal configuration method of solar-thermal power stations could ensure an accurate allocation of installed capacity.When the installed capacity of the solar-thermal power station is 1×106 kW,the transient voltage recovery index(TVRI)is 0.359,which has a strong voltage support capacity for the system.Based on the results of this work,the optimal configuration of the installed capacity of the solar-thermal power plant can improve peak shaving performance,transient voltage support capability,and new energy consumption while satisfying the Direct Current(DC)outgoing transmission premise.
基金supported by the National Natural Science Foundation of China(51075147)863 Project(2012AA041803)
文摘At present the mechanical model of the interac- tion between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine (TBM) on-site data. This is not in line with the actual rock-breaking movement of the disc cutter and impedes to some extent the research on the rock-breaking mechanism, wear mechanism and design theory. Therefore, our study focuses on the interaction between the slantingly installed disc cutter and rock, developing a model in accordance with the actual rock-breaking movement. Displacement equations are established through an analysis of the velocity vector at the rock-breaking point of the disc cutter blade; the func- tional relationship between the displacement parameters at the rock-breaking point and its rectangular coordinates is established through an analysis of micro-displacement vectors at the rock-breaking point, thus leading to the geometric equations of rock deformation caused by the slantingly installed disc cutter. Considering the basically linear relationship between the cutting force of disc cutters and the rock deformation before and after the leap break of rock, we express the constitutive relations of rock deformation as generalized Hooke's law and analyze the effect of the slanting installa- tion angle of disc cutters on the rock-breaking force. This will, as we hope, make groundbreaking contributions to the development of the design theory and installation practice of TBM.
文摘This paper proposes a novel method to calculate the best installed capacity of pumped storage power station. First, we choose the day with maximum load as the typical day for every month and simulate the system running in two cases of whether the pumped storage power station is put into operation. The difference of the total coal consumption between the two cases is the peak load shifting benefit. Furthermore, we build load model and power generation model to calculate the benefit of emergency use and frequency modulation, which are the major projects of dynamic benefits. At last, on the premise of ensuring the system requirements, the developed method employs the maximum benefit of the unit capacity as the objective function to get the best installed capacity of pumped storage power station by simulations. Tests on a provincial power grid have shown that the developed method which combines of load characteristics, electric structure and other factors can get the best installed capacity of pumped storage power station easily and has a certain guiding significance for the planning and construction of the pumped storage power station.
基金supported by National Natural Science Foundation of China(Grant 51475163)National Hightech R&D Program of China(863 Program,Grant 2012AA041803)
文摘At present, disc cutters of a full face rock tunnel boring machine are mostly mounted in the traditional way. Practical use in engineering projects reveals that this installation method not only heavily affects the operation life of disc cutters, but also increases the energy consumption of a full face rock tunnel boring machine. To straighten out this issue, therefore, a rock-breaking model is developed for disc cutters' movement after the research on the rock breaking of forward-slanting disc cutters. Equations of its displacement are established based on the analysis of velocity vector of a disc cutter's rock-breaking point. The functional relations then are brought forward between the displacement parameters of a rock-breaking point and its coordinate through the analysis of micro displacement of a rock-breaking point. Thus, the geometric equations of rock deformation are derived for the forward-slanting installation of disc cutters. With a linear relationship remaining between the acting force and its deformation either before or after the leap breaking, the constitutive relation of rock deformation can be expressed in the form of generalized Hooke law, hence the comparative analysis of the variation in the resistance of rock to the disc cutters mounted in the forward-slanting way with that in the traditional way. It is discovered that with the same penetration, strain of the rock in contact with forwardslanting disc cutters is apparently on the decline, in otherwords, the resistance of rock to disc cutters is reduced. Thus wear of disc cutters resulted from friction is lowered and energy consumption is correspondingly decreased. It will be useful for the development of installation and design theory of disc cutters, and significant for the breakthrough in the design of full face rock tunnel boring machine.
文摘There are two kinds of generating equipment in a firmly con-nected power network,one is water power plants(shortenedas“water power”,below),the other is thermal power plants(includingcoal-fired,oil-fired and nuclear power plants,but the analysis in thisarticle is based mainly on coal-fired power generation.And they willbe shortened as“thermal power”below).As far as power output isconcerned,when the share of water power installed capacity
文摘China's installed capacity of storage batteries to power electric vehicles saw a year-on-year increase of 9.2 percent in 2019,industry data has shown.The rise came amid the country's stepped-up efforts for greener growth,including the use of new energy vehicles (NEV).In 2019,the installed capacity of storage batteries reached 62.2 gigawatt hours,according to data from the China automotive power battery industry innovation alliance.
文摘According to the statistics of energy industry,China's installed capacity of renewable energy power reached 1.002 billion kW in 2021,accounting for 43.5%of the country's total installed capacity,which was 10.2 percentage higher than that of 2015.In the total renewable energy power,the installed capacities of hydropower,wind power,solar power and biomass power reached 385 million kW,299 million kW,282 million kW and 35.34 million kW,respectively,continuing to be the number one in the world.
文摘The journalist learned from the "National Gas Security Working Conference" held recently that the coal seam gas power generation has been rapidly developed in recent years.As of July 2009,within the SGCC's business area,the power generation
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51809231 and 51988101)。
文摘A new dynamically installed plate anchor, the Flying Wing Anchor~?, has been developed as a sustainable anchor concept for deep-water offshore wind turbines. The anchor is firstly installed by free-fall penetration and then followed by drag embedment. If the anchor is subjected to environmental loads, it dives deeper to mobilize a higher capacity. This study presents a series of free-fall penetration tests with model anchors in different weights to assess the anchor behavior during the free-fall penetration performance in one-layer soil with a constant shear strength profile. Anchor velocities and embedment depths were measured by a magnetometer. An energy-based model and a force-based model were calibrated against the test results of model anchors with different weights. Based on the calibrated force-based model, a series of design charts were developed to estimate the embedment depth of anchors in different sizes and with different impact velocities in various marine clays. The framework to plot design charts presented herein can be potentially applied to other dynamically installed anchors to predict embedment depth in engineering practice.
文摘Solar Photovoltaic (PV) can be considered as one of the most reliable and promising renewable systems. This is of great importance for developing countries like Nigeria especially in the rural communities where there is little or no access to electricity. The use of solar energy will no doubt contribute to the improvement of the living conditions of these villagers. Solar PV systems have been installed in some villages in Nigeria but unfortunately, the expected benefits from using these systems have been jeopardized. The objective of this work is to embark on performance assessments of in- stalled Solar PV system in Oke-Agunla, Akure local government of Ondo State in Nigeria. Visits were conducted to the village;equipments on ground were examined while the people were interviewed. Both functional and non-functional facilities were traced to their manufacturers using the identification data on them and rated to ensure their efficiencies. Energy demands were also prorated, and observed the need to improve on the present energy supplied. Results of the assessments shows that PV facilities used were inadequate, trained technicians were not available giving room for quacks working on the facilities occasionally resulted in further complications and poor facilities maintenance. The assessment result shows that just 14.52% of the 4.5 kW installed solar PV was utilized due to significant malfunctioning and deterioration in performance. It can be concluded from this study that the installed solar PV systems was inefficient as a result of poor maintenance, lack of technical know-how and inability of the project contractors or managers to take these factors into consideration while embarking on the solar PV installations.
文摘In the first half of this year,the installed capacity of photovoltaic power generation was 78.42 GW(one GW is equal to one million kilowatts),an increase of over 150%year-on-year,close to the installed capacity data of last year(87.41 GW),accounting for 56%of the installed capacity of new power sources in the first half of this year.By the end of June,the cumulative installed capacity of photovoltaic in China was about 470 million kilowatts,and photovoltaic has become the second largest installed power source in China,second only to coal-fired power.
文摘The positive figures of last year confirm the strength,resilience,and prospects of the Chinese economy.CHINA’S government work report delivered to the 2024“Two Sessions”in early March released some important statistics.The GDP surpassed RMB 126 trillion,an increase of 5.2 percent.A total of 12.44 million urban jobs were added,and the average surveyed urban unemployment rate stood at 5.2 percent by average.The consumer price index(CPI)rose by 0.2 percent.The production and sales of new-energy vehicles accounted for over 60 percent of the world’s total.Grain output hit a record high of 695 million tonnes.The installed renewable energy capacity surpassed its thermal power for the first time in Chinese history,accounting for over half of newly installed renewable energy capacity worldwide.The per capita disposable income of residents also rose by 6.1 percent nationwide.
文摘Avivid three-dimensional rendering of a bridge appeared on the intelligent monitor and evaluation platform at Beijing Yunlu Technology Co.,Ltd.,pointing to key factors of bridge health.Real-time status,events,transportation navigation,and traffic conditions were all tracked on the screen.Numerous sensors installed on bridge track every minor dynamic change on the bridge surface and perform digital analysis.
文摘"In 2023,China's photovoltaic industry continued to maintain a rapid development momentum,with an additional installed capacity of more than 216 GW,accounting for more than half of the global total.The cumulative installed capacity is close to 610 GW,which helps the installed capacity of renewable energy surpass that of thermal power historically.In 2023,the output value of the domestic photovoltaic manufacturing industry exceeded RMB1.75 trillion,a year-on-year increase of 17.1%,and the output of the four main industrial chains of polysilicon.
文摘Here are some of the achievements China made in 2023:GDP exceeded 126 trillion yuan($17.43 trillion)with a growth of 5.2 percent;12.44 million new urban jobs were created;average surveyed unemployment rate in urban areas was 5.2 percent;consumer price index increased by 0.2 percent;new energy vehicle production and sales accounted for more than 60 percent of the global share;grain output reached a record high of 695 billion kg;installed renewable energy capacity surpassed thermal power capacity for the first time in history,and China accounted for over half of newly installed renewable energy capacity worldwide;per-capita disposable income of residents increased by 6.1 percent…