Electric system planning with high variable renewable energy(VRE)penetration levels has attracted great attention world-wide.Electricity production of VRE highly depends on the weather conditions and thus involves lar...Electric system planning with high variable renewable energy(VRE)penetration levels has attracted great attention world-wide.Electricity production of VRE highly depends on the weather conditions and thus involves large variability,uncertainty,and low-capacity credit.This gives rise to significant challenges for power system planning.Currently,many solutions are proposed to address the issue of operational flexibility inadequacy,including flexibility retrofit of thermal units,inter-regional transmission,electricity energy storage,and demand response(DR).Evidently,the performance and the cost of various solutions are different.It is relevant to explore the optimal portfolio to satisfy the flexibility requirement for a renewable dominated system and the role of each flexibility source.In this study,the value of diverse DR flexibilities was examined and a stochastic investment planning model considering DR is proposed.Two types of DRs,namely interrupted DR and transferred DR,were modeled.Chronological load and renewable generation curves with 8760 hours within a whole year were reduced to 4 weekly scenarios to accelerate the optimization.Clustered unit commitment constraints for accommodating variability of renewables were incorporated.Case studies based on IEEE RTS-96 system are reported to demonstrate the effectiveness of the proposed method and the DR potential to avoid energy storage investment.展开更多
The economic and social progress under the new era has put forward new requirements for logistics talents.Based on the teaching concept of OBE-CDIO as well as the training program and objectives of logistics managemen...The economic and social progress under the new era has put forward new requirements for logistics talents.Based on the teaching concept of OBE-CDIO as well as the training program and objectives of logistics management major in Guangzhou Maritime University,this study analyzes and discusses how the Logistics System Planning and Design course,which is targeted at students majoring in logistics management,enables the students to meet the graduation requirements by virtue of realizing the course objectives.展开更多
The system planning of the Northwest China 330 kV Power System from present to the year 2000 is introduced in this paper. Some technical problems arising from the system planning, such as network configuration, system...The system planning of the Northwest China 330 kV Power System from present to the year 2000 is introduced in this paper. Some technical problems arising from the system planning, such as network configuration, system stability and reactive power compensation etc. are also briefly summarized.展开更多
In recent years,renewable energy(RE)penetration has become an important target in power systems.However,RE power is affected by climate change and has strong randomness and volatility.Adequate transmission capacity an...In recent years,renewable energy(RE)penetration has become an important target in power systems.However,RE power is affected by climate change and has strong randomness and volatility.Adequate transmission capacity and energy storage systems(ESSs)are conducive to the integration of RE.Therefore,coordinated transmission renewable–storage expansion planning(TRSEP)is an effective decision-making approach to cope with the impacts of climate change and achieve the development tar-get of RE penetration.Electricity trading between different systems is common;therefore,in addition to the penetration of RE into the internal loads of the system,the proportion of RE generation in tie lines is gaining attention,making analyses of the RE transmission path necessary.Referring to the flow of carbon emissions,this paper defines the RE power flow density to track the transmission path of RE.Next,a TRSEP model is proposed that can clearly distinguish the RE transmission path into internal loads,exter-nal loads,and energy losses.To address the presence of bilinear terms in the proposed model,the McCormick method is applied,and a customized feasibility correction strategy is designed to obtain a good feasible solution.Numerical results from case studies are provided to verify the rationality and effectiveness of the approach proposed in this paper.展开更多
A real-life milk run system designing problem of an engine manufacturer adopted JIT(just-in-time)production is studied.In the process of milk run system planning and design,the supply base is identified and a supplier...A real-life milk run system designing problem of an engine manufacturer adopted JIT(just-in-time)production is studied.In the process of milk run system planning and design,the supply base is identified and a supplier site map is plotted for an arrangement of routes on which parts are periodically collected in a JIT manner from many scattered suppliers.With unit load designing,vehicle choosing and fleet sizing,pickup routing,vehicle assigning and scheduling problems are studied.Among these problems,a CVRP problem is identified and formulated as the key optimization in designing this milk run system,and it is solved through an optimization process.This tactical planning and optimization process gives a good solution to the real problem,and may shed light on the planning of similar systems.展开更多
This paper presents the framework of probabilistic power system planning.The basic concepts,criteria,procedure,analysis techniques and tasks of probabilistic power system planning are discussed.Probabilistic reliabili...This paper presents the framework of probabilistic power system planning.The basic concepts,criteria,procedure,analysis techniques and tasks of probabilistic power system planning are discussed.Probabilistic reliability evaluation and probabilistic economic assessment are two key steps.It should also be recognized that probabilistic system planning has a wider coverage than these two aspects.An actual example using a utility system is given to demonstrate an application of probabilistic transmission development planning.展开更多
An approach for the integrated optimization of the construction/expansion capacity of high-voltage/ medium-voltage (HV/MV) substations and the configuration of MV radial distribution network was presented using plant ...An approach for the integrated optimization of the construction/expansion capacity of high-voltage/ medium-voltage (HV/MV) substations and the configuration of MV radial distribution network was presented using plant growth simulation algorithm (PGSA). In the optimization process, fixed costs correspondent to the investment in lines and substations and the variable costs associated to the operation of the system were considered under the constraints of branch capacity, substation capacity and bus voltage. The optimization variables considerably reduce the dimension of variables and speed up the process of optimizing. The effectiveness of the proposed approach was tested by a distribution system planning.展开更多
Increasing wind power integration and coal-fired unit retirements increases the strain on the power system’s spinning reserve and increases the pressure on peak regulation.With the ability to stock extra power genera...Increasing wind power integration and coal-fired unit retirements increases the strain on the power system’s spinning reserve and increases the pressure on peak regulation.With the ability to stock extra power generation and supply the peak load,the energy storage system(ESS)can alleviate the rising demand on the spinning reserve and play an increasingly important role in the power system.In this paper,a trilevel robust ESS planning model is proposed to accommodate uncertain wind power investment as well as coal-fired unit retirement.The upper-level of this model is to determine the planning scheme of ESSs,which iteratively takes the worst-case scenario of wind power investment and coal-fired unit retirement into consideration.The middle-level and lower-level of this model are to make the optimal daily economic dispatch under the worst-case realizations of uncertainties.We derive an equivalent reformulation of the proposed robust ESS planning model and solve it with a dual column-and-constraint generation algorithm.Case studies are conducted using the IEEE RTS-79 system.The results demonstrate the superiority of the proposed planning method in comparison with other methods.Furthermore,the effects of the capital cost of ESS,the expected proportion of wind power,and the uncertainty budget on the development of ESS are studied.Taking the uncertainties of unit retirement and wind power investment into consideration achieves a better trade-off between the ESS investment cost and the operational cost.展开更多
Under the pressure of environmental issues,decarbonization of the entire energy system has emerged as a prevalent strategy worldwide.The evolution of China’s power system will increasingly emphasize the integration o...Under the pressure of environmental issues,decarbonization of the entire energy system has emerged as a prevalent strategy worldwide.The evolution of China’s power system will increasingly emphasize the integration of variable renewable energy(VRE).However,the rapid growth of VRE will pose substantial challenges to the power system,highlighting the importance of power system planning.This letter introduces Grid Optimal Planning Tool(GOPT),a planning tool,and presents the key findings of our research utilizing GOPT to analyze the transition pathway of China’s power system towards dual carbon goals.Furthermore,the letter offers insights into key technologies essential for driving the future transition of China’s power system.展开更多
The high penetration of variable renewable energy raises a flexibility challenge in the power system.This raises the necessity of considering the adequacy of flexibility in power system planning.However,the flexibilit...The high penetration of variable renewable energy raises a flexibility challenge in the power system.This raises the necessity of considering the adequacy of flexibility in power system planning.However,the flexibility of the power system covers a wide range of timescales,from seconds to months.This poses difficulties in planning of multi-timescale flexible resources.This paper proposes a new perspective on the modeling and planning of multi-timescale flexible resources in power systems with high penetration of variable renewable energy.The operational boundaries of flexible resources are transformed into a characteristic domain,where flexibility at different timescales can be added and the balance of flexible supply and demand can be expressed as algebraic equations.Such modeling facilitates rigorous multi-timescale flexibility balance metrics.Furthermore,a planning method for multi-timescale flexibility is proposed based on the model in the characteristic domain.The proposed planning method is tested using data from China's Xinjiang provincial power grid.Results show the proposed method can characterize multi-timescale flexibility with high accuracy,thus making it possible to fully account for flexibility at different timescales.展开更多
Renewable generation is rapidly increasing and transforming power systems toward“new-type power systems”.The integration of renewable energy resources necessitates a shift from conventional grid-following converters...Renewable generation is rapidly increasing and transforming power systems toward“new-type power systems”.The integration of renewable energy resources necessitates a shift from conventional grid-following converters(GFLs)to advanced grid-forming controls.Although grid-forming converters(GFMs)provide grid support and enhance system stability under weak grid conditions,their deployment requires more robust hardware,complex control algorithms and system operation constraints,resulting in planning and operational trade-offs between system stability and cost efficiency.This paper studies the underexplored question of how many GFMs are needed from a techno-economic perspective.The holistic analysis integrates long-term planning,short-term operational strategies and dynamic stability considerations,thereby supporting large-scale renewable integration while ensuring system security and economic benefits.展开更多
Thyristor valve is one of the key equipments for ultra high voltage direct current(UHVDC) power transmission projects.Before being installed on site,they need to be tested in a laboratory in order to verify their oper...Thyristor valve is one of the key equipments for ultra high voltage direct current(UHVDC) power transmission projects.Before being installed on site,they need to be tested in a laboratory in order to verify their operational performance to satisfy the technical specification of project related.Test facilities for operational tests of thyristor valves are supposed to enable to undertake more severe electrical stresses than those being applied in the thyristor valves under test(test objects).On the other hand,the stresses applied into the test objects are neither higher nor lower than specified by the specification,because inappropriate stresses applied would result in incorrect evaluation of performance on the test objects,more seriously,would cuase the damage of test objects with expensive cost losing.Generally,the process of operational tests is complicated and performed in a complex synthetic test circuit(hereafter as STC),where there are a lot of sensors used for measuring,monitoring and protection on line to ensure that the test circuit functions in good condition.Therefore,the measuring systems embedded play a core role in STC,acting like "eyes".Based on the first project of building up a STC in China,experience of planning measuring systems is summarized so as to be referenced by related engineers.展开更多
Under the background of low-carbon demand, an integrated energy system is the main direction of energy system development. Integrated Energy System (IES) breaks through technical, market and management barriers of tra...Under the background of low-carbon demand, an integrated energy system is the main direction of energy system development. Integrated Energy System (IES) breaks through technical, market and management barriers of traditional energy systems, and it makes unified planning and scheduling for electricity, gas, heat, cold, etc. However, IES contains a variety of energy forms, and those energy forms are coupled with each other. Its planning and operation are challenging problems. Therefore, this paper proposes an IES planning model, which comprehensively considers optimization of the equipment configuration, interconnection of multiple energy stations, renewable energy integration, and optimal operation strategy. During the planning decision-making, planners can use this model to analyze and evaluate the impact of various factors on the planning indicators. Using the proposed model, an IES composed of several buildings in a street block is planned in detail and the effectiveness of the proposed planning model and its solution method is proved. The case study results show the total cost and carbon emission of the model considering both energy station interconnection and RES integration are reduced by 20.2% and 41.5%.展开更多
Multi-energy system(MES)is crucial for the development of smart cities.This paper summarises the research progress and achievements from an engineering case study in China which aims at enhancing MES energy efficiency...Multi-energy system(MES)is crucial for the development of smart cities.This paper summarises the research progress and achievements from an engineering case study in China which aims at enhancing MES energy efficiency.Key theories and technologies were tested at an MES demonstration site in Hunan,China,using both software and hardware systems which improve significantly in energy efficiency,carbon savings,environmental and economic benefits.Specifically,the optimal operation modes proposed in this paper achieves a best-case scenario of 9.97 tons of CO_(2) savings,26.4%lower than conventional systems.The findings provide crucial guidance for policymakers and industry stakeholders which aims to implement sustainable energy solutions in future urban planning.展开更多
Concerning the integration of large-scale wind power,an integrated model of generation and transmission expansion planning is proposed based on the assessment of the value of steady state and dynamic security.In the a...Concerning the integration of large-scale wind power,an integrated model of generation and transmission expansion planning is proposed based on the assessment of the value of steady state and dynamic security.In the assessment of security value,the unit commitment simulation based on the predicted hourly load and wind power output data in the planning horizon is used to evaluate the costs of preventive control,emergency control and social losses due to the uncertainty of load and wind power.The cost of preventive control consists of the fuel cost of power generation,the environmental cost and the load shedding cost.This not only provides a systematic method of security assessment of power system expansion planning schemes,but also broadens the perspective of power system planning from the technology and economic assessment to the measure of the whole social value.In the assessment process,the preventive control and emergency control of cascading failures are also presented,which provides a convincing tool for cascading failure analysis of planning schemes and makes the security assessment more comprehensive and reasonable.The proposed model and method have been demonstrated by the assessment of two power system planning schemes on the New England 10-genarator 39-bus System.The importance of considering the value of security and simulating hourly system operation for the planning horizon,in expansion planning of power system with integration of large-scale wind power,has been confirmed.展开更多
Roof bolts such as rock bolts and cable bolts provide structural support in underground mines.Frequent assessment of these support structures is critical to maintain roof stability and minimise safety risks in undergr...Roof bolts such as rock bolts and cable bolts provide structural support in underground mines.Frequent assessment of these support structures is critical to maintain roof stability and minimise safety risks in underground environments.This study proposes a robust workflow to classify roof bolts in 3 D point cloud data and to generate maps of roof bolt density and spacing.The workflow was evaluated for identifying roof bolts in an underground coal mine with suboptimal lighting and global navigation satellite system(GNSS)signals not available.The approach is based on supervised classification using the multi-scale Canupo classifier coupled with a random sample consensus(RANSAC)shape detection algorithm to provide robust roof bolt identification.The issue of sparseness in point cloud data has been addressed through upsampling by using a moving least squares method.The accuracy of roof bolt identification was measured by correct identification of roof bolts(true positives),unidentified roof bolts(false negatives),and falsely identified roof bolts(false positives)using correctness,completeness,and quality metrics.The proposed workflow achieved correct identification of 89.27%of the roof bolts present in the test area.However,considering the false positives and false negatives,the overall quality metric was reduced to 78.54%.展开更多
Following the deregulation of the power industry,transmission expansion planning(TEP)has become more complicated due to the presence of uncertainties and conflicting objectives in a market environment.Also,the growing...Following the deregulation of the power industry,transmission expansion planning(TEP)has become more complicated due to the presence of uncertainties and conflicting objectives in a market environment.Also,the growing concern on global warming highlights the importance of considering carbon pricing policies during TEP.In this paper,a probabilistic TEP approach is proposed with the integration of a chance constrained load curtailment index.The formulated dynamic programming problem is solved by a hybrid solution algorithm in an iterative process.The performance of our approach is demonstrated by case studies on a modified IEEE 14-bus system.Simulation results prove that our approach can provide network planners with comprehensive information regarding effects of uncertainties on TEP schemes,allowing them to adjust planning strategies based on their risk aversion levels or financial constraints.展开更多
We address the problem of optimally re-routing the feeders of urban distribution network in Milano,Italy,which presents some peculiarities and significant design challenges.Milano has two separate medium-voltage(MV)di...We address the problem of optimally re-routing the feeders of urban distribution network in Milano,Italy,which presents some peculiarities and significant design challenges.Milano has two separate medium-voltage(MV)distribution networks,previously operated by two different utilities,which grew up independently and incoordinately.This results in a system layout which is inefficient,redundant,and difficult to manage due to different operating procedures.The current utility UNARETI,which is in charge of the overall distribution system,aims at optimally integrating the two MV distribution networks and moving to a new specific layout that offers advantages from the perspectives of reliability and flexibility.We present a mixed-integer programming(MIP)approach for the design of a new network configuration satisfying the so-called 2-step ladder layout required by the planner.The model accounts for the main electrical constraints such as power flow equations,thermal limits of high-voltage(HV)/MV substation transformers,line thermal limits,and the maximum number of customers per feeder.Real power losses are taken into account via a quadratic formulation and a piecewise linear approximation.Computational tests on a small-scale system and on a part of the Milano distribution network are reported.展开更多
This survey paper provides a critical overview of optimization formulations for planning and operation of islanded microgrids,including optimization objectives,constraints,and control variables.The optimization approa...This survey paper provides a critical overview of optimization formulations for planning and operation of islanded microgrids,including optimization objectives,constraints,and control variables.The optimization approaches reviewed address methods both for increasing the resiliency of advanced distribution systems and electrification of remote communities.This paper examines over 120 individual optimization studies and discovers that all optimizations studies of islanded microgrids are based on formulations selecting a combination of 16 possible objective functions,14 constraints,and 13 control variables.Each of the objectives,constraints,and variables are discussed exhaustively both from the perspective of their importance to islanded microgrids and chronological trends in their popularity.展开更多
Adequacy is a key concern of power system planning,which refers to the availability of sufficient facilities to meet demand.The capacity value(CV)of variable renewable energy(VRE)generation represents its equivalent c...Adequacy is a key concern of power system planning,which refers to the availability of sufficient facilities to meet demand.The capacity value(CV)of variable renewable energy(VRE)generation represents its equivalent contribution to system adequacy,in comparison to conventional generators.While VRE continues to grow and increasingly dominates the generation portfolio,its CV is becoming non-negligible,with the corresponding impact mechanisms becoming more complicated and nuanced.In this paper,the concept of CV is revisited by analyzing how VRE contributes to power system balancing at a high renewable energy penetration level.A generalized loss function is incorporated into the CV evaluation framework considering the adequacy of the power system.An analytical method for the CV evaluation of VRE is then derived using the statistical properties of both hourly load and VRE generation.Through the explicit CV expression,several critical impact factors,including the VRE generation variance,source-load correlation,and system adequacy level,are identified and discussed.Case studies demonstrate the accuracy and effectiveness of the proposed method in comparison to the traditional capacity factor-based methods and convolution-based methods.In the IEEERTS79 test system,the CV of a 2500 MW wind farm(with40%renewable energy penetration level)is found to be 6.8%of its nameplate capacity.Additionally,the sensitivity of CV to various impact factors in power systems with high renewable energy penetration is analyzed.展开更多
基金jointly supported by Youth Program of National Natural Science Foundation of China(No.51907100)Technical Program of Global Energy Interconnection Group Co.,Ltd(No.1100/2020-75001B)
文摘Electric system planning with high variable renewable energy(VRE)penetration levels has attracted great attention world-wide.Electricity production of VRE highly depends on the weather conditions and thus involves large variability,uncertainty,and low-capacity credit.This gives rise to significant challenges for power system planning.Currently,many solutions are proposed to address the issue of operational flexibility inadequacy,including flexibility retrofit of thermal units,inter-regional transmission,electricity energy storage,and demand response(DR).Evidently,the performance and the cost of various solutions are different.It is relevant to explore the optimal portfolio to satisfy the flexibility requirement for a renewable dominated system and the role of each flexibility source.In this study,the value of diverse DR flexibilities was examined and a stochastic investment planning model considering DR is proposed.Two types of DRs,namely interrupted DR and transferred DR,were modeled.Chronological load and renewable generation curves with 8760 hours within a whole year were reduced to 4 weekly scenarios to accelerate the optimization.Clustered unit commitment constraints for accommodating variability of renewables were incorporated.Case studies based on IEEE RTS-96 system are reported to demonstrate the effectiveness of the proposed method and the DR potential to avoid energy storage investment.
基金the 2019 Guangzhou Educational Science Planning Project(201912027)2018 Guangzhou Maritime College Innovation and Strong School Project(F410608)+2 种基金2020 Industry-University Cooperation Collaborative Education Project(Jiao Gao Si Han[2021]No.3202002325060,202002325052,202002325050)Teaching Quality and Teaching Reform Project of Logistics Engineering Key Major of Guangdong Provincial Undergraduate Colleges and Universities(Yue Gao Han[2020]19)Guangzhou Education Policy Research Project(ZCYJ20109)。
文摘The economic and social progress under the new era has put forward new requirements for logistics talents.Based on the teaching concept of OBE-CDIO as well as the training program and objectives of logistics management major in Guangzhou Maritime University,this study analyzes and discusses how the Logistics System Planning and Design course,which is targeted at students majoring in logistics management,enables the students to meet the graduation requirements by virtue of realizing the course objectives.
文摘The system planning of the Northwest China 330 kV Power System from present to the year 2000 is introduced in this paper. Some technical problems arising from the system planning, such as network configuration, system stability and reactive power compensation etc. are also briefly summarized.
基金supported by State Key Laboratory of Electrical Insulation and Power Equipment(EIPE22119).
文摘In recent years,renewable energy(RE)penetration has become an important target in power systems.However,RE power is affected by climate change and has strong randomness and volatility.Adequate transmission capacity and energy storage systems(ESSs)are conducive to the integration of RE.Therefore,coordinated transmission renewable–storage expansion planning(TRSEP)is an effective decision-making approach to cope with the impacts of climate change and achieve the development tar-get of RE penetration.Electricity trading between different systems is common;therefore,in addition to the penetration of RE into the internal loads of the system,the proportion of RE generation in tie lines is gaining attention,making analyses of the RE transmission path necessary.Referring to the flow of carbon emissions,this paper defines the RE power flow density to track the transmission path of RE.Next,a TRSEP model is proposed that can clearly distinguish the RE transmission path into internal loads,exter-nal loads,and energy losses.To address the presence of bilinear terms in the proposed model,the McCormick method is applied,and a customized feasibility correction strategy is designed to obtain a good feasible solution.Numerical results from case studies are provided to verify the rationality and effectiveness of the approach proposed in this paper.
基金The National Key Technology R&D Program of China during the 11th Five-Year Plan Period(No.2006BAH02A06)
文摘A real-life milk run system designing problem of an engine manufacturer adopted JIT(just-in-time)production is studied.In the process of milk run system planning and design,the supply base is identified and a supplier site map is plotted for an arrangement of routes on which parts are periodically collected in a JIT manner from many scattered suppliers.With unit load designing,vehicle choosing and fleet sizing,pickup routing,vehicle assigning and scheduling problems are studied.Among these problems,a CVRP problem is identified and formulated as the key optimization in designing this milk run system,and it is solved through an optimization process.This tactical planning and optimization process gives a good solution to the real problem,and may shed light on the planning of similar systems.
基金supported in part by the National 111 Project of China(B08036).
文摘This paper presents the framework of probabilistic power system planning.The basic concepts,criteria,procedure,analysis techniques and tasks of probabilistic power system planning are discussed.Probabilistic reliability evaluation and probabilistic economic assessment are two key steps.It should also be recognized that probabilistic system planning has a wider coverage than these two aspects.An actual example using a utility system is given to demonstrate an application of probabilistic transmission development planning.
基金the National Natural Science Foundation of China (No. 50747025)the Postdoctoral Science Foundation of China (No. 20060400648)+1 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars (No. 2005383)the Shanghai Key Scienceand Technology Research Program (No. 041612012)
文摘An approach for the integrated optimization of the construction/expansion capacity of high-voltage/ medium-voltage (HV/MV) substations and the configuration of MV radial distribution network was presented using plant growth simulation algorithm (PGSA). In the optimization process, fixed costs correspondent to the investment in lines and substations and the variable costs associated to the operation of the system were considered under the constraints of branch capacity, substation capacity and bus voltage. The optimization variables considerably reduce the dimension of variables and speed up the process of optimizing. The effectiveness of the proposed approach was tested by a distribution system planning.
基金This work was supported by the National Key R&D Program of China(2016YFB0900100)the National Natural Science Foundation of China(51907123,51807116).
文摘Increasing wind power integration and coal-fired unit retirements increases the strain on the power system’s spinning reserve and increases the pressure on peak regulation.With the ability to stock extra power generation and supply the peak load,the energy storage system(ESS)can alleviate the rising demand on the spinning reserve and play an increasingly important role in the power system.In this paper,a trilevel robust ESS planning model is proposed to accommodate uncertain wind power investment as well as coal-fired unit retirement.The upper-level of this model is to determine the planning scheme of ESSs,which iteratively takes the worst-case scenario of wind power investment and coal-fired unit retirement into consideration.The middle-level and lower-level of this model are to make the optimal daily economic dispatch under the worst-case realizations of uncertainties.We derive an equivalent reformulation of the proposed robust ESS planning model and solve it with a dual column-and-constraint generation algorithm.Case studies are conducted using the IEEE RTS-79 system.The results demonstrate the superiority of the proposed planning method in comparison with other methods.Furthermore,the effects of the capital cost of ESS,the expected proportion of wind power,and the uncertainty budget on the development of ESS are studied.Taking the uncertainties of unit retirement and wind power investment into consideration achieves a better trade-off between the ESS investment cost and the operational cost.
基金supported by the National Natural Science Foundation of China(No.52130702,No.52177093)。
文摘Under the pressure of environmental issues,decarbonization of the entire energy system has emerged as a prevalent strategy worldwide.The evolution of China’s power system will increasingly emphasize the integration of variable renewable energy(VRE).However,the rapid growth of VRE will pose substantial challenges to the power system,highlighting the importance of power system planning.This letter introduces Grid Optimal Planning Tool(GOPT),a planning tool,and presents the key findings of our research utilizing GOPT to analyze the transition pathway of China’s power system towards dual carbon goals.Furthermore,the letter offers insights into key technologies essential for driving the future transition of China’s power system.
基金supported by the Science and Technology Project of State Grid Corporation of China"The technology and application of model refinement and aggregation to support multi-level,multiagent and multiperiod dispatch"(5100-202099497A-0-0-00).
文摘The high penetration of variable renewable energy raises a flexibility challenge in the power system.This raises the necessity of considering the adequacy of flexibility in power system planning.However,the flexibility of the power system covers a wide range of timescales,from seconds to months.This poses difficulties in planning of multi-timescale flexible resources.This paper proposes a new perspective on the modeling and planning of multi-timescale flexible resources in power systems with high penetration of variable renewable energy.The operational boundaries of flexible resources are transformed into a characteristic domain,where flexibility at different timescales can be added and the balance of flexible supply and demand can be expressed as algebraic equations.Such modeling facilitates rigorous multi-timescale flexibility balance metrics.Furthermore,a planning method for multi-timescale flexibility is proposed based on the model in the characteristic domain.The proposed planning method is tested using data from China's Xinjiang provincial power grid.Results show the proposed method can characterize multi-timescale flexibility with high accuracy,thus making it possible to fully account for flexibility at different timescales.
基金supported in part by the Carbon Neutrality and Energy System Transformation project and in part by EPSRC under Grant EP/Y025946/1.
文摘Renewable generation is rapidly increasing and transforming power systems toward“new-type power systems”.The integration of renewable energy resources necessitates a shift from conventional grid-following converters(GFLs)to advanced grid-forming controls.Although grid-forming converters(GFMs)provide grid support and enhance system stability under weak grid conditions,their deployment requires more robust hardware,complex control algorithms and system operation constraints,resulting in planning and operational trade-offs between system stability and cost efficiency.This paper studies the underexplored question of how many GFMs are needed from a techno-economic perspective.The holistic analysis integrates long-term planning,short-term operational strategies and dynamic stability considerations,thereby supporting large-scale renewable integration while ensuring system security and economic benefits.
基金Project Supported by National Development and Reform Commission(No.[2006]2709)
文摘Thyristor valve is one of the key equipments for ultra high voltage direct current(UHVDC) power transmission projects.Before being installed on site,they need to be tested in a laboratory in order to verify their operational performance to satisfy the technical specification of project related.Test facilities for operational tests of thyristor valves are supposed to enable to undertake more severe electrical stresses than those being applied in the thyristor valves under test(test objects).On the other hand,the stresses applied into the test objects are neither higher nor lower than specified by the specification,because inappropriate stresses applied would result in incorrect evaluation of performance on the test objects,more seriously,would cuase the damage of test objects with expensive cost losing.Generally,the process of operational tests is complicated and performed in a complex synthetic test circuit(hereafter as STC),where there are a lot of sensors used for measuring,monitoring and protection on line to ensure that the test circuit functions in good condition.Therefore,the measuring systems embedded play a core role in STC,acting like "eyes".Based on the first project of building up a STC in China,experience of planning measuring systems is summarized so as to be referenced by related engineers.
基金supported by the project of“Sustainable urban power supply through intelligent control and enhanced restoration of AC/DC networks(SUPER)”(52061635104).
文摘Under the background of low-carbon demand, an integrated energy system is the main direction of energy system development. Integrated Energy System (IES) breaks through technical, market and management barriers of traditional energy systems, and it makes unified planning and scheduling for electricity, gas, heat, cold, etc. However, IES contains a variety of energy forms, and those energy forms are coupled with each other. Its planning and operation are challenging problems. Therefore, this paper proposes an IES planning model, which comprehensively considers optimization of the equipment configuration, interconnection of multiple energy stations, renewable energy integration, and optimal operation strategy. During the planning decision-making, planners can use this model to analyze and evaluate the impact of various factors on the planning indicators. Using the proposed model, an IES composed of several buildings in a street block is planned in detail and the effectiveness of the proposed planning model and its solution method is proved. The case study results show the total cost and carbon emission of the model considering both energy station interconnection and RES integration are reduced by 20.2% and 41.5%.
基金supported by the National Nature Science Foundation of China,Grant No:U22B20104the International Science and Technology Cooperation Program of China,Grant No:2022YFE0129300.
文摘Multi-energy system(MES)is crucial for the development of smart cities.This paper summarises the research progress and achievements from an engineering case study in China which aims at enhancing MES energy efficiency.Key theories and technologies were tested at an MES demonstration site in Hunan,China,using both software and hardware systems which improve significantly in energy efficiency,carbon savings,environmental and economic benefits.Specifically,the optimal operation modes proposed in this paper achieves a best-case scenario of 9.97 tons of CO_(2) savings,26.4%lower than conventional systems.The findings provide crucial guidance for policymakers and industry stakeholders which aims to implement sustainable energy solutions in future urban planning.
文摘Concerning the integration of large-scale wind power,an integrated model of generation and transmission expansion planning is proposed based on the assessment of the value of steady state and dynamic security.In the assessment of security value,the unit commitment simulation based on the predicted hourly load and wind power output data in the planning horizon is used to evaluate the costs of preventive control,emergency control and social losses due to the uncertainty of load and wind power.The cost of preventive control consists of the fuel cost of power generation,the environmental cost and the load shedding cost.This not only provides a systematic method of security assessment of power system expansion planning schemes,but also broadens the perspective of power system planning from the technology and economic assessment to the measure of the whole social value.In the assessment process,the preventive control and emergency control of cascading failures are also presented,which provides a convincing tool for cascading failure analysis of planning schemes and makes the security assessment more comprehensive and reasonable.The proposed model and method have been demonstrated by the assessment of two power system planning schemes on the New England 10-genarator 39-bus System.The importance of considering the value of security and simulating hourly system operation for the planning horizon,in expansion planning of power system with integration of large-scale wind power,has been confirmed.
基金financially supported by the Australian Coal Industry’s Research Program(ACARP)Project C27057。
文摘Roof bolts such as rock bolts and cable bolts provide structural support in underground mines.Frequent assessment of these support structures is critical to maintain roof stability and minimise safety risks in underground environments.This study proposes a robust workflow to classify roof bolts in 3 D point cloud data and to generate maps of roof bolt density and spacing.The workflow was evaluated for identifying roof bolts in an underground coal mine with suboptimal lighting and global navigation satellite system(GNSS)signals not available.The approach is based on supervised classification using the multi-scale Canupo classifier coupled with a random sample consensus(RANSAC)shape detection algorithm to provide robust roof bolt identification.The issue of sparseness in point cloud data has been addressed through upsampling by using a moving least squares method.The accuracy of roof bolt identification was measured by correct identification of roof bolts(true positives),unidentified roof bolts(false negatives),and falsely identified roof bolts(false positives)using correctness,completeness,and quality metrics.The proposed workflow achieved correct identification of 89.27%of the roof bolts present in the test area.However,considering the false positives and false negatives,the overall quality metric was reduced to 78.54%.
文摘Following the deregulation of the power industry,transmission expansion planning(TEP)has become more complicated due to the presence of uncertainties and conflicting objectives in a market environment.Also,the growing concern on global warming highlights the importance of considering carbon pricing policies during TEP.In this paper,a probabilistic TEP approach is proposed with the integration of a chance constrained load curtailment index.The formulated dynamic programming problem is solved by a hybrid solution algorithm in an iterative process.The performance of our approach is demonstrated by case studies on a modified IEEE 14-bus system.Simulation results prove that our approach can provide network planners with comprehensive information regarding effects of uncertainties on TEP schemes,allowing them to adjust planning strategies based on their risk aversion levels or financial constraints.
文摘We address the problem of optimally re-routing the feeders of urban distribution network in Milano,Italy,which presents some peculiarities and significant design challenges.Milano has two separate medium-voltage(MV)distribution networks,previously operated by two different utilities,which grew up independently and incoordinately.This results in a system layout which is inefficient,redundant,and difficult to manage due to different operating procedures.The current utility UNARETI,which is in charge of the overall distribution system,aims at optimally integrating the two MV distribution networks and moving to a new specific layout that offers advantages from the perspectives of reliability and flexibility.We present a mixed-integer programming(MIP)approach for the design of a new network configuration satisfying the so-called 2-step ladder layout required by the planner.The model accounts for the main electrical constraints such as power flow equations,thermal limits of high-voltage(HV)/MV substation transformers,line thermal limits,and the maximum number of customers per feeder.Real power losses are taken into account via a quadratic formulation and a piecewise linear approximation.Computational tests on a small-scale system and on a part of the Milano distribution network are reported.
文摘This survey paper provides a critical overview of optimization formulations for planning and operation of islanded microgrids,including optimization objectives,constraints,and control variables.The optimization approaches reviewed address methods both for increasing the resiliency of advanced distribution systems and electrification of remote communities.This paper examines over 120 individual optimization studies and discovers that all optimizations studies of islanded microgrids are based on formulations selecting a combination of 16 possible objective functions,14 constraints,and 13 control variables.Each of the objectives,constraints,and variables are discussed exhaustively both from the perspective of their importance to islanded microgrids and chronological trends in their popularity.
基金supported in part by the National Key R&D Program of China(No.2022YFB2403300)in part by the Scientific&Technical Project of State Grid Shanghai Electric Power Company(No.SGSHDK00DWJS2310470)in part by the Scientific&Technical Project of China Electric Power Planning&Engineering Institute(No.K202316)。
文摘Adequacy is a key concern of power system planning,which refers to the availability of sufficient facilities to meet demand.The capacity value(CV)of variable renewable energy(VRE)generation represents its equivalent contribution to system adequacy,in comparison to conventional generators.While VRE continues to grow and increasingly dominates the generation portfolio,its CV is becoming non-negligible,with the corresponding impact mechanisms becoming more complicated and nuanced.In this paper,the concept of CV is revisited by analyzing how VRE contributes to power system balancing at a high renewable energy penetration level.A generalized loss function is incorporated into the CV evaluation framework considering the adequacy of the power system.An analytical method for the CV evaluation of VRE is then derived using the statistical properties of both hourly load and VRE generation.Through the explicit CV expression,several critical impact factors,including the VRE generation variance,source-load correlation,and system adequacy level,are identified and discussed.Case studies demonstrate the accuracy and effectiveness of the proposed method in comparison to the traditional capacity factor-based methods and convolution-based methods.In the IEEERTS79 test system,the CV of a 2500 MW wind farm(with40%renewable energy penetration level)is found to be 6.8%of its nameplate capacity.Additionally,the sensitivity of CV to various impact factors in power systems with high renewable energy penetration is analyzed.
