The types of operation play a key role in facilitating tourism consumption and economic development in a tourism destination. By adopting evolutionary economic geography theory, the paper analyzes the types of operati...The types of operation play a key role in facilitating tourism consumption and economic development in a tourism destination. By adopting evolutionary economic geography theory, the paper analyzes the types of operation in West Lake Scenic Area from 1978 to 2013. First, an evolution process consisting of four stages is underpinned, and they are: the new establishment stage, the preliminary development stage, the speedup development stage, and the stabilized maturity stage. Specifically, the distinct characteristics associated with operation types are compared and evaluated at different stages throughout the process. The evolution trees are introduced to scrutinize types of operation development. The results of evolution trees demonstrate the substantial increase in both numbers and types. Second, by applying GIS spatial analysis, the paper also analyzes the spatial evolution characteristics on the types of operation, and the results unveil the co-existence of centripetal and centrifugal forces: the processes of spatial agglomeration and spatial dispersion. More specifically, we recognize the spatial process includes the emergence of node and concentration(1978–1995), the sparse distribution and intensity reduction(1996–2002), the patchy distribution and spatial agglomeration intensification(2003–2008), the dispersed distribution and core area agglomeration(2009–2013). Lastly, path dependence on resource endowment, government and market innovation, knowledge learning and spillover can reasonably explain the types of operation evolution. In conclusion, the evolutionary economic geography theories provide new theoretical and empirical perspectives for tourism policy analysis. At the same time, our comprehensive evidences impart more comprehensive insights and offer useful managerial and policy implications.展开更多
This paper discusses a float-coded genetic algorithm and its application to the optimization of the power plant operation concerning the simulation problem of economical operation for power plant systems. The method p...This paper discusses a float-coded genetic algorithm and its application to the optimization of the power plant operation concerning the simulation problem of economical operation for power plant systems. The method proposed realizes the load optimization between generating units of power plants and their loads, solves the problem of influence of a unit plant pause spoilage and load variance on the optimal plant combination and load, and finally establishes a simulation platform for the power plant economical operation.展开更多
In this paper the analysis is presented on the economic performance of the electrical equipment industry in 2010.Substantial increase was seen in both the economic aggregate indices such as production and sales,and ec...In this paper the analysis is presented on the economic performance of the electrical equipment industry in 2010.Substantial increase was seen in both the economic aggregate indices such as production and sales,and economic efficiency indices such as profits.Increase of indices that reflect foreign trade situation of the industry,such as import volume,export volume,gross import and export volume,and export delivery volume were prominent in particular.The industry has completely stepped out of the "negative growth" predicament in 2009,comprehensively outperformed the level in 2008,and recovered true growth.The economic situation of the electrical equipment industry in 2011 is also predicted in this paper.展开更多
Since 2017,the global economic recovery has increased tendency.The economic growth of main countries and districts has promoted.The Chinese economy welcomes the successful commencement of the 19th National Congress in...Since 2017,the global economic recovery has increased tendency.The economic growth of main countries and districts has promoted.The Chinese economy welcomes the successful commencement of the 19th National Congress in transforming from high-speed growing economy into high-quality development.With the promotion of new era and new dynamic power,展开更多
The growing integration of renewable energy sources manifests as an effective strategy for reducing carbon emissions. This paper strives to efficiently approximate the set of optimal scheduling plans(OSPs) to enhance ...The growing integration of renewable energy sources manifests as an effective strategy for reducing carbon emissions. This paper strives to efficiently approximate the set of optimal scheduling plans(OSPs) to enhance the performance of the steady-state adaptive cruise method(SACM) of power grid, improving the ability of dealing with operational uncertainties. Initially, we provide a mathematical definition of the exact boxconstrained economic operating region(EBC-EOR) for the power grid and its dispatchable components. Following this, we introduce an EBC-EOR formulation algorithm and the corresponding bi-level optimization models designed to explore the economic operating boundaries. In addition, we propose an enhanced big-M method to expedite the computation of the EBCEOR. Finally, the effectiveness of the EBC-EOR formulation, its economic attributes, correlation with the scheduling plan underpinned by model predictive control, and the significant improvement in computational efficiency(over twelvefold) are verified through case studies conducted on two test systems..展开更多
With the development of smart meters,a realtime pricing(RTP)demand response is becoming possible for households in distribution networks.The power flow can be bidirectional in distribution networks which become smarte...With the development of smart meters,a realtime pricing(RTP)demand response is becoming possible for households in distribution networks.The power flow can be bidirectional in distribution networks which become smarter with distributed generators(DGs).It is expensive to import electricity from the generation far from load centers because of the cost of power loss and network use,so that it is more economical to use electricity generated by local distributed generators.Therefore,in order to curtail operating costs of distribution networks,this paper proposes a model of economic optimization conducted by distribution network operators.The electricity purchasing costs for distribution network operators are minimized by optimizing electric power from transmission systems and local distributed generators.Further,based on price elasticity,the formulations of load demand considering RTP are proposed with economic optimization of distribution networks.The economic optimization problems are resolved by an interior point method.The case study shows that peak load demand can be reduced about 3.5%because the household RTP and electricity purchasing costs of distribution network operators can save 28.86£every hour.展开更多
With the increasing connection of controllable devices to isolated community microgrid,an economic operation model of isolated community microgrid based on the temperature regulation characteristics of temperature con...With the increasing connection of controllable devices to isolated community microgrid,an economic operation model of isolated community microgrid based on the temperature regulation characteristics of temperature controlling devices composed of wind turbine,micro-gas turbine,energy storage battery and heat pump is proposed.With full consideration of various economic costs,including fuel cost,start-stop cost,energy storage battery depletion expense and penalty for wind curtailment,the model is solved by hybrid particle swarm optimization(HPSO)algorithm.The optimal output of the micro-sources and total operating cost of the system in the scheduling cycle are also obtained.The case study demonstrates that temperature adjustment of temperature controlling devices can adjust the power load indirectly and increase the schedulability of the isolated community microgrid,and reduce the operating cost of the microgrid.展开更多
Given the different energy rates of multiple types of power generation units,different operation plans affect the economy of microgrids.Limited by load and power generation forecasting technologies,the economic superi...Given the different energy rates of multiple types of power generation units,different operation plans affect the economy of microgrids.Limited by load and power generation forecasting technologies,the economic superiority of day-ahead plans is unable to be fully utilized because of the fluctuation of loads and power sources.In this regard,a two-stage correction strategy-based real-time dispatch method for the economic operation of microgrids is proposed.Based on the optimal day-ahead economic operation plan,unbalanced power is validly allocated in two stages in terms of power increment and current power,which maintains the economy of the day-ahead plan.Further,for operating point offset during real-time correction,a rolling dispatch method is introduced to dynamically update the system operation plan.Finally,the results verify the effectiveness of the proposed method.展开更多
Cotton Textile:Price Rising in Imp.& Exp.Trade According to State Administration of Statistics,from Jan.to March,3896 statistics-worthy(whose annul output exceeding 20 million yuan)yarn manufacturers produced yarn...Cotton Textile:Price Rising in Imp.& Exp.Trade According to State Administration of Statistics,from Jan.to March,3896 statistics-worthy(whose annul output exceeding 20 million yuan)yarn manufacturers produced yarn 6.18 million tons,rising 12.54% from the展开更多
DC microgrids are gaining more attention with the increased penetration of various DC sources such as solar photovoltaic systems, fuel cells, batteries, etc., and DC loads. Due to the rapid integration of these compon...DC microgrids are gaining more attention with the increased penetration of various DC sources such as solar photovoltaic systems, fuel cells, batteries, etc., and DC loads. Due to the rapid integration of these components into the existing power system, the importance of DC microgrids has reached a salient point. Compared with conventional AC systems, DC systems are free from synchronization issues, reactive power control, frequency control, etc., and are more reliable and efficient.However, many challenges need to be addressed for utilizing DC power to its full potential. The absence of natural current zero is a significant issue in protecting DC systems. In addition,the stability of the DC microgrid, which relies on inertia, needs to be considered during system design. Moreover, power quality and communication issues are also significant challenges in DC microgrids. This paper presents a review of various value streams of DC microgrids including architectures, protection schemes, power quality, inertia, communication, and economic operation. In addition, comparisons between different microgrid configurations, the state-of-the-art projects of DC microgrid, and future trends are also set forth for further studies.展开更多
Over the past decades,both agriculture and power systems have faced serious problems,such as the power supply shortage in agriculture,and difficulties of clean energy consump-tion in the power system.To address and ov...Over the past decades,both agriculture and power systems have faced serious problems,such as the power supply shortage in agriculture,and difficulties of clean energy consump-tion in the power system.To address and overcome these issues,this paper proposes an idea to combine smart agriculture and clean energy consumption,use surplus clean energy to supply agriculture production,and utilize smart agriculture to support power system with clean energy penetration.A comprehensive review has been conducted to first depict the roadmap of coupling a agriculture-clean energy system,analyze their feasibilities and advantages.The recent technologies and bottlenecks are summa-rized and evaluated for the development of a combined system consisting of smart agriculture production and clean energy consumption.Several case studies are introduced to explore the mutual benefits of agriculture-clean energy systems in both the energy and food industries.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41230631,41471130)
文摘The types of operation play a key role in facilitating tourism consumption and economic development in a tourism destination. By adopting evolutionary economic geography theory, the paper analyzes the types of operation in West Lake Scenic Area from 1978 to 2013. First, an evolution process consisting of four stages is underpinned, and they are: the new establishment stage, the preliminary development stage, the speedup development stage, and the stabilized maturity stage. Specifically, the distinct characteristics associated with operation types are compared and evaluated at different stages throughout the process. The evolution trees are introduced to scrutinize types of operation development. The results of evolution trees demonstrate the substantial increase in both numbers and types. Second, by applying GIS spatial analysis, the paper also analyzes the spatial evolution characteristics on the types of operation, and the results unveil the co-existence of centripetal and centrifugal forces: the processes of spatial agglomeration and spatial dispersion. More specifically, we recognize the spatial process includes the emergence of node and concentration(1978–1995), the sparse distribution and intensity reduction(1996–2002), the patchy distribution and spatial agglomeration intensification(2003–2008), the dispersed distribution and core area agglomeration(2009–2013). Lastly, path dependence on resource endowment, government and market innovation, knowledge learning and spillover can reasonably explain the types of operation evolution. In conclusion, the evolutionary economic geography theories provide new theoretical and empirical perspectives for tourism policy analysis. At the same time, our comprehensive evidences impart more comprehensive insights and offer useful managerial and policy implications.
文摘This paper discusses a float-coded genetic algorithm and its application to the optimization of the power plant operation concerning the simulation problem of economical operation for power plant systems. The method proposed realizes the load optimization between generating units of power plants and their loads, solves the problem of influence of a unit plant pause spoilage and load variance on the optimal plant combination and load, and finally establishes a simulation platform for the power plant economical operation.
文摘In this paper the analysis is presented on the economic performance of the electrical equipment industry in 2010.Substantial increase was seen in both the economic aggregate indices such as production and sales,and economic efficiency indices such as profits.Increase of indices that reflect foreign trade situation of the industry,such as import volume,export volume,gross import and export volume,and export delivery volume were prominent in particular.The industry has completely stepped out of the "negative growth" predicament in 2009,comprehensively outperformed the level in 2008,and recovered true growth.The economic situation of the electrical equipment industry in 2011 is also predicted in this paper.
文摘Since 2017,the global economic recovery has increased tendency.The economic growth of main countries and districts has promoted.The Chinese economy welcomes the successful commencement of the 19th National Congress in transforming from high-speed growing economy into high-quality development.With the promotion of new era and new dynamic power,
基金supported by the Science and Technology Project of State Grid Corporation(No.5400-202099286A-0-0-00).
文摘The growing integration of renewable energy sources manifests as an effective strategy for reducing carbon emissions. This paper strives to efficiently approximate the set of optimal scheduling plans(OSPs) to enhance the performance of the steady-state adaptive cruise method(SACM) of power grid, improving the ability of dealing with operational uncertainties. Initially, we provide a mathematical definition of the exact boxconstrained economic operating region(EBC-EOR) for the power grid and its dispatchable components. Following this, we introduce an EBC-EOR formulation algorithm and the corresponding bi-level optimization models designed to explore the economic operating boundaries. In addition, we propose an enhanced big-M method to expedite the computation of the EBCEOR. Finally, the effectiveness of the EBC-EOR formulation, its economic attributes, correlation with the scheduling plan underpinned by model predictive control, and the significant improvement in computational efficiency(over twelvefold) are verified through case studies conducted on two test systems..
文摘With the development of smart meters,a realtime pricing(RTP)demand response is becoming possible for households in distribution networks.The power flow can be bidirectional in distribution networks which become smarter with distributed generators(DGs).It is expensive to import electricity from the generation far from load centers because of the cost of power loss and network use,so that it is more economical to use electricity generated by local distributed generators.Therefore,in order to curtail operating costs of distribution networks,this paper proposes a model of economic optimization conducted by distribution network operators.The electricity purchasing costs for distribution network operators are minimized by optimizing electric power from transmission systems and local distributed generators.Further,based on price elasticity,the formulations of load demand considering RTP are proposed with economic optimization of distribution networks.The economic optimization problems are resolved by an interior point method.The case study shows that peak load demand can be reduced about 3.5%because the household RTP and electricity purchasing costs of distribution network operators can save 28.86£every hour.
基金the National Natural Science Foundation of China under Grant 51677011.
文摘With the increasing connection of controllable devices to isolated community microgrid,an economic operation model of isolated community microgrid based on the temperature regulation characteristics of temperature controlling devices composed of wind turbine,micro-gas turbine,energy storage battery and heat pump is proposed.With full consideration of various economic costs,including fuel cost,start-stop cost,energy storage battery depletion expense and penalty for wind curtailment,the model is solved by hybrid particle swarm optimization(HPSO)algorithm.The optimal output of the micro-sources and total operating cost of the system in the scheduling cycle are also obtained.The case study demonstrates that temperature adjustment of temperature controlling devices can adjust the power load indirectly and increase the schedulability of the isolated community microgrid,and reduce the operating cost of the microgrid.
文摘Given the different energy rates of multiple types of power generation units,different operation plans affect the economy of microgrids.Limited by load and power generation forecasting technologies,the economic superiority of day-ahead plans is unable to be fully utilized because of the fluctuation of loads and power sources.In this regard,a two-stage correction strategy-based real-time dispatch method for the economic operation of microgrids is proposed.Based on the optimal day-ahead economic operation plan,unbalanced power is validly allocated in two stages in terms of power increment and current power,which maintains the economy of the day-ahead plan.Further,for operating point offset during real-time correction,a rolling dispatch method is introduced to dynamically update the system operation plan.Finally,the results verify the effectiveness of the proposed method.
文摘Cotton Textile:Price Rising in Imp.& Exp.Trade According to State Administration of Statistics,from Jan.to March,3896 statistics-worthy(whose annul output exceeding 20 million yuan)yarn manufacturers produced yarn 6.18 million tons,rising 12.54% from the
文摘DC microgrids are gaining more attention with the increased penetration of various DC sources such as solar photovoltaic systems, fuel cells, batteries, etc., and DC loads. Due to the rapid integration of these components into the existing power system, the importance of DC microgrids has reached a salient point. Compared with conventional AC systems, DC systems are free from synchronization issues, reactive power control, frequency control, etc., and are more reliable and efficient.However, many challenges need to be addressed for utilizing DC power to its full potential. The absence of natural current zero is a significant issue in protecting DC systems. In addition,the stability of the DC microgrid, which relies on inertia, needs to be considered during system design. Moreover, power quality and communication issues are also significant challenges in DC microgrids. This paper presents a review of various value streams of DC microgrids including architectures, protection schemes, power quality, inertia, communication, and economic operation. In addition, comparisons between different microgrid configurations, the state-of-the-art projects of DC microgrid, and future trends are also set forth for further studies.
基金This work was supported by the New Century Higher Education Teaching Reform Project of Sichuan University under Grant SCU8007and the Inter-disciplinary Training Project for Talents of Sichuan University under grant SCUKG056.
文摘Over the past decades,both agriculture and power systems have faced serious problems,such as the power supply shortage in agriculture,and difficulties of clean energy consump-tion in the power system.To address and overcome these issues,this paper proposes an idea to combine smart agriculture and clean energy consumption,use surplus clean energy to supply agriculture production,and utilize smart agriculture to support power system with clean energy penetration.A comprehensive review has been conducted to first depict the roadmap of coupling a agriculture-clean energy system,analyze their feasibilities and advantages.The recent technologies and bottlenecks are summa-rized and evaluated for the development of a combined system consisting of smart agriculture production and clean energy consumption.Several case studies are introduced to explore the mutual benefits of agriculture-clean energy systems in both the energy and food industries.
