In order to specify the overvoltage and insulation level of equipments in ±1 100 kV UHVDC converter stations,the arrester configuration scheme and some basic parameters for ±1 100 kV Zhundong converter stati...In order to specify the overvoltage and insulation level of equipments in ±1 100 kV UHVDC converter stations,the arrester configuration scheme and some basic parameters for ±1 100 kV Zhundong converter station are proposed.Overvoltage of equipments in AC system,valve hall,DC busbar,and neutral busbar are also calculated in accordance with the fundamental principles of arrester configuration for UHV converter stations and the existing experiences in insulation coordination of ±800 kV UHVDC converter stations.The work is done also for specifing insulation levels for ±1 100 kV UHVDC converter stations of the ±1 100 kV UHVDC power transmission project from Zhundong to Sichuan in China.Thus,the recommended insulation margins that determine the insulation levels of converter station equipments are proposed: the insulation margins for thyristor valves are 10%/10%/15% for switching impulse/ lightning impulse/ steer front impulse; the insulation levels of lighting and swtiching impulses are recommended as 2 600 kV and 2 150 kV respectively for 1 100 kV DC buses,and as 2 250 kV and 2 100 kV respectively for equipments at the valve side of high-voltage Y/Y converter transformers.展开更多
Most surveying works for mapping or GIS applications are performed with total station. Due to the remote nature of many of the sites surveyed, the surveys are often done in unprojected, local, assumed coordinate syste...Most surveying works for mapping or GIS applications are performed with total station. Due to the remote nature of many of the sites surveyed, the surveys are often done in unprojected, local, assumed coordinate systems. However, without the survey data projected in real world coordinates, the range of possible analyses is limited and the value of existing imagery, elevation models, and hydrologic layers cannot be exploited. This requires a transformation from the local assumed to the real world coordinate systems. There are various built-in and add-in tools to perform transformations through GIS programs. This paper studies the effect of using Georeferencing tool, Spatial Adjustment tool (Affine and similarity) and CHaMP tool on the precision and relative accuracy of total station survey. This transformation requires real-world coordinates of at least two control points, which can be collected from different sources. This paper also studies the effect of using geodetic GPS, hand-held GPS, Google Earth (GE) and Bing Basemaps as sources for control points on the precision and relative accuracy of total station survey. These effects have been tested by using 111 points covered area of 60,000 m2and the results have shown that the CHaMP tool is the best for preserving the relative accuracy of the transformed points. The Georeferencing and spatial adjustment (similarity) tools give the same results and their accuracy are between 1/1000 and 1/300 depending on the source of control points. The results have also shown that the cornerstone to preserve the precision and relative accuracy of the transformed coordinates is the relative position of the control points despite their source.展开更多
As a good measure to tackle the challenges from energy shortages and environmental pollution,Electric Vehicles(EVs)have entered a period of rapid growth.Battery swapping station is a very important way of energy suppl...As a good measure to tackle the challenges from energy shortages and environmental pollution,Electric Vehicles(EVs)have entered a period of rapid growth.Battery swapping station is a very important way of energy supply to EVs,and it is urgently needed to explore a coordinated control strategy to effectively smooth the load fluctuation in order to adopt the large-scale EVs.Considering bidirectional power flow between the station and power grid,this paper proposed a SFLA-based control strategy to smooth the load profile.Finally,compared simulations were performed according to the related data.Compared to particle swarm optimization(PSO)method,the presented SFLA-based strategy can effectively lower the peak-valley difference with the faster convergence rate and higher convergence precision.It is important for the swapping station that energy exchanging mode can supply energy for large-scale EVs with a smoother load profile than one-way charging mode.展开更多
5G基站、分布式光伏(distributed photovoltaic,DPV)等分布式资源大规模参与配电网经济与电能质量等多目标优化调度,致使配电网调控模型决策变量复杂、求解时间慢等问题凸显。为此,提出一种考虑5G基站调控潜力和多资源协同的配电网分层...5G基站、分布式光伏(distributed photovoltaic,DPV)等分布式资源大规模参与配电网经济与电能质量等多目标优化调度,致使配电网调控模型决策变量复杂、求解时间慢等问题凸显。为此,提出一种考虑5G基站调控潜力和多资源协同的配电网分层分区优化方法。首先,考虑5G基站通信流量波动特性,建立计及闲置荷电状态(state of charge,SOC)约束的5G基站调控潜力模型。基于此,再建立配电网分层分区优化模型。上层以配电网综合效益最优为目标进行集中式调度,从而确定配电网分组投切电容器组、静止无功发生器等自身资源的动作方案。下层为分区调度,结合电压-功率灵敏度和考虑5G基站通信负荷的源荷不匹配度指标进行配电网物理分区,建立面向5G基站闲置SOC和DPV剩余容量的配电网分区协调优化模型,并采用二阶锥规划和同步型交替方向乘子法相结合的混合算法进行求解。最后,以改进的IEEE33节点配电网为算例,分析验证了所提方法的有效性。结果表明,所提方法能够提高配电网调控模型的求解能力,并提升配电网经济性和电压质量。展开更多
Transit-oriented development(TOD)is increasingly recognized as a key strategy for enhancing transportation efficiency,environmental sustainability,and economic vitality while fostering inclusive communities in dense,m...Transit-oriented development(TOD)is increasingly recognized as a key strategy for enhancing transportation efficiency,environmental sustainability,and economic vitality while fostering inclusive communities in dense,multifunctional urban areas.However,the relationship between TOD’s economic benefits and social equity remains underexplored.This study critically evaluates TOD in Dalian,China,introducing the expanded Node-Place-Economy(NPE)model,which integrates economic and social dimensions into the traditional Node-Place model.The NPE model offers a comprehensive framework for assessing TOD effectiveness,particularly in balancing economic growth and equitable resource distribution.The research highlights significant disparities between central and peripheral regions,with central areas performing better in both economic and social equity,while peripheral areas exacerbate socio-economic inequalities.Through spatial analysis and the Coupling Coordination Index(CCI),the study identifies factors influencing the synergy between economic vitality and social equity,such as the density of commercial,sports,and entertainment facilities.The findings emphasize the need for more equitable TOD planning,suggesting that future urban developments should prioritize social inclusiveness alongside economic efficiency.This research expands the theoretical foundation of TOD and offers practical insights for urban planners aiming to achieve sustainable and inclusive urban development.展开更多
To address the limitations of traditional planning methods in handling complex scenarios such as multi-feeder or substation cluster supply under high photovoltaic(PV)penetration,this paper proposes a collaborative con...To address the limitations of traditional planning methods in handling complex scenarios such as multi-feeder or substation cluster supply under high photovoltaic(PV)penetration,this paper proposes a collaborative configuration optimization method of soft open points(SOPs)and distributed multi-energy stations with spatiotemporal coordination and complementarity to reduce renewable energy curtailment.First,a shared strategy of multiple types of resources is proposed based on an SOP-enabled flexible distribution network.Second,a distributed hydrogen-based multi-energy coupling system(DHMECS)is developed.Then,a DHMECS siting model considering inter-feeder resource sharing is formulated.Finally,a configuration model of SOP and DHMECS is proposed,incorporating a partitioned autonomous operation strategy that considers spatiotemporal coordination and complementarity.The proposed method is validated on the improved Portugal 54-node and 219-node distribution networks,and the results demonstrate that it mitigates severe voltage violations and PV curtailment,enhances partitioned autonomous operation capabilities,and addresses the challenges of complex planning scenarios involving multi-feeder or substation cluster supply.展开更多
Electromagnetic detection satellite（EDS） is a type of Earth observation satellite（EOS）. Satellites observation and data down-link scheduling plays a significant role in improving the efficiency of satellite observ...Electromagnetic detection satellite（EDS） is a type of Earth observation satellite（EOS）. Satellites observation and data down-link scheduling plays a significant role in improving the efficiency of satellite observation systems. However, the current works mainly focus on the scheduling of imaging satellites, little work focuses on the scheduling of EDSes for its specific requirements.And current works mainly schedule satellite resources and data down-link resources separately, not considering them in a globally optimal perspective. The EDSes and data down-link resources are scheduled in an integrated process and the scheduling result is searched globally. Considering the specific constraints of EDS, a coordinate scheduling model for EDS observation tasks and data transmission jobs is established and an algorithm based on the genetic algorithm is proposed. Furthermore, the convergence of our algorithm is proved. To deal with some specific constraints, a solution repairing algorithm of polynomial computing time is designed. Finally, some experiments are conducted to validate the correctness and practicability of our scheduling algorithms.展开更多
基金supported by National Basic Research Program of China(973 Program)(2011CB209405)
文摘In order to specify the overvoltage and insulation level of equipments in ±1 100 kV UHVDC converter stations,the arrester configuration scheme and some basic parameters for ±1 100 kV Zhundong converter station are proposed.Overvoltage of equipments in AC system,valve hall,DC busbar,and neutral busbar are also calculated in accordance with the fundamental principles of arrester configuration for UHV converter stations and the existing experiences in insulation coordination of ±800 kV UHVDC converter stations.The work is done also for specifing insulation levels for ±1 100 kV UHVDC converter stations of the ±1 100 kV UHVDC power transmission project from Zhundong to Sichuan in China.Thus,the recommended insulation margins that determine the insulation levels of converter station equipments are proposed: the insulation margins for thyristor valves are 10%/10%/15% for switching impulse/ lightning impulse/ steer front impulse; the insulation levels of lighting and swtiching impulses are recommended as 2 600 kV and 2 150 kV respectively for 1 100 kV DC buses,and as 2 250 kV and 2 100 kV respectively for equipments at the valve side of high-voltage Y/Y converter transformers.
文摘Most surveying works for mapping or GIS applications are performed with total station. Due to the remote nature of many of the sites surveyed, the surveys are often done in unprojected, local, assumed coordinate systems. However, without the survey data projected in real world coordinates, the range of possible analyses is limited and the value of existing imagery, elevation models, and hydrologic layers cannot be exploited. This requires a transformation from the local assumed to the real world coordinate systems. There are various built-in and add-in tools to perform transformations through GIS programs. This paper studies the effect of using Georeferencing tool, Spatial Adjustment tool (Affine and similarity) and CHaMP tool on the precision and relative accuracy of total station survey. This transformation requires real-world coordinates of at least two control points, which can be collected from different sources. This paper also studies the effect of using geodetic GPS, hand-held GPS, Google Earth (GE) and Bing Basemaps as sources for control points on the precision and relative accuracy of total station survey. These effects have been tested by using 111 points covered area of 60,000 m2and the results have shown that the CHaMP tool is the best for preserving the relative accuracy of the transformed points. The Georeferencing and spatial adjustment (similarity) tools give the same results and their accuracy are between 1/1000 and 1/300 depending on the source of control points. The results have also shown that the cornerstone to preserve the precision and relative accuracy of the transformed coordinates is the relative position of the control points despite their source.
文摘As a good measure to tackle the challenges from energy shortages and environmental pollution,Electric Vehicles(EVs)have entered a period of rapid growth.Battery swapping station is a very important way of energy supply to EVs,and it is urgently needed to explore a coordinated control strategy to effectively smooth the load fluctuation in order to adopt the large-scale EVs.Considering bidirectional power flow between the station and power grid,this paper proposed a SFLA-based control strategy to smooth the load profile.Finally,compared simulations were performed according to the related data.Compared to particle swarm optimization(PSO)method,the presented SFLA-based strategy can effectively lower the peak-valley difference with the faster convergence rate and higher convergence precision.It is important for the swapping station that energy exchanging mode can supply energy for large-scale EVs with a smoother load profile than one-way charging mode.
文摘5G基站、分布式光伏(distributed photovoltaic,DPV)等分布式资源大规模参与配电网经济与电能质量等多目标优化调度,致使配电网调控模型决策变量复杂、求解时间慢等问题凸显。为此,提出一种考虑5G基站调控潜力和多资源协同的配电网分层分区优化方法。首先,考虑5G基站通信流量波动特性,建立计及闲置荷电状态(state of charge,SOC)约束的5G基站调控潜力模型。基于此,再建立配电网分层分区优化模型。上层以配电网综合效益最优为目标进行集中式调度,从而确定配电网分组投切电容器组、静止无功发生器等自身资源的动作方案。下层为分区调度,结合电压-功率灵敏度和考虑5G基站通信负荷的源荷不匹配度指标进行配电网物理分区,建立面向5G基站闲置SOC和DPV剩余容量的配电网分区协调优化模型,并采用二阶锥规划和同步型交替方向乘子法相结合的混合算法进行求解。最后,以改进的IEEE33节点配电网为算例,分析验证了所提方法的有效性。结果表明,所提方法能够提高配电网调控模型的求解能力,并提升配电网经济性和电压质量。
基金supported by the National Natural Science Foundation of China(Grant No.52308011).
文摘Transit-oriented development(TOD)is increasingly recognized as a key strategy for enhancing transportation efficiency,environmental sustainability,and economic vitality while fostering inclusive communities in dense,multifunctional urban areas.However,the relationship between TOD’s economic benefits and social equity remains underexplored.This study critically evaluates TOD in Dalian,China,introducing the expanded Node-Place-Economy(NPE)model,which integrates economic and social dimensions into the traditional Node-Place model.The NPE model offers a comprehensive framework for assessing TOD effectiveness,particularly in balancing economic growth and equitable resource distribution.The research highlights significant disparities between central and peripheral regions,with central areas performing better in both economic and social equity,while peripheral areas exacerbate socio-economic inequalities.Through spatial analysis and the Coupling Coordination Index(CCI),the study identifies factors influencing the synergy between economic vitality and social equity,such as the density of commercial,sports,and entertainment facilities.The findings emphasize the need for more equitable TOD planning,suggesting that future urban developments should prioritize social inclusiveness alongside economic efficiency.This research expands the theoretical foundation of TOD and offers practical insights for urban planners aiming to achieve sustainable and inclusive urban development.
基金supported by Smart Grid-National Science and Technology Major Project(No.2024ZD0800800)Science and Technology Project of State Grid Corporation of China“Low-carbon and Reliable Urban Power Distribution System Demonstration Project”(No.SGTJDK00DWJS2400298).
文摘To address the limitations of traditional planning methods in handling complex scenarios such as multi-feeder or substation cluster supply under high photovoltaic(PV)penetration,this paper proposes a collaborative configuration optimization method of soft open points(SOPs)and distributed multi-energy stations with spatiotemporal coordination and complementarity to reduce renewable energy curtailment.First,a shared strategy of multiple types of resources is proposed based on an SOP-enabled flexible distribution network.Second,a distributed hydrogen-based multi-energy coupling system(DHMECS)is developed.Then,a DHMECS siting model considering inter-feeder resource sharing is formulated.Finally,a configuration model of SOP and DHMECS is proposed,incorporating a partitioned autonomous operation strategy that considers spatiotemporal coordination and complementarity.The proposed method is validated on the improved Portugal 54-node and 219-node distribution networks,and the results demonstrate that it mitigates severe voltage violations and PV curtailment,enhances partitioned autonomous operation capabilities,and addresses the challenges of complex planning scenarios involving multi-feeder or substation cluster supply.
基金supported by the National Natural Science Foundation of China(6110118461174159)
文摘Electromagnetic detection satellite（EDS） is a type of Earth observation satellite（EOS）. Satellites observation and data down-link scheduling plays a significant role in improving the efficiency of satellite observation systems. However, the current works mainly focus on the scheduling of imaging satellites, little work focuses on the scheduling of EDSes for its specific requirements.And current works mainly schedule satellite resources and data down-link resources separately, not considering them in a globally optimal perspective. The EDSes and data down-link resources are scheduled in an integrated process and the scheduling result is searched globally. Considering the specific constraints of EDS, a coordinate scheduling model for EDS observation tasks and data transmission jobs is established and an algorithm based on the genetic algorithm is proposed. Furthermore, the convergence of our algorithm is proved. To deal with some specific constraints, a solution repairing algorithm of polynomial computing time is designed. Finally, some experiments are conducted to validate the correctness and practicability of our scheduling algorithms.
