With maturing deregulated environment for electricity market, cost of transmission congestion becomes a major issue for power system operation. Uniform Marginal Price and Locational Marginal Price (LMP) are the two pr...With maturing deregulated environment for electricity market, cost of transmission congestion becomes a major issue for power system operation. Uniform Marginal Price and Locational Marginal Price (LMP) are the two practical pricing schemes on energy pricing and congestion cost allocation, which are based on different mechanisms. In this paper, these two pricing schemes are introduced in detail respectively. Also, the modified IEEE-14-bus system is used as a test system to calculate the allocated congestion cost by using these two pricing schemes.展开更多
To encourage retailers to form cooperative alliances to jointly replenish inventory,considering that the supplier provides a flexible lead time and quantity discount to retailers,a model of average total cost per unit...To encourage retailers to form cooperative alliances to jointly replenish inventory,considering that the supplier provides a flexible lead time and quantity discount to retailers,a model of average total cost per unit time of periodic joint replenishment is constructed,and an approximate algorithm,which can satisfy the requirement of any given precision,is given.The cost allocation rule in the core of the joint replenishment game is designed based on the cooperative game theory.The numerical experiment results show that the proposed algorithm can quickly solve the joint replenishment problem when the item number is not greater than 640.The retailer's cost saving rate is always greater than 0,and it increases with the increase in quantity discount and fixed cost after adopting the given cost allocation rule.With the increase in the safety stock level,the retailer's cost saving rate increases first and then decreases;and the retailer's cost saving rate increases with the increase in the size of the alliance,but it decreases as the number of product category increases.The proposed cost allocation rule can reduce the retailer's cost up to 20%,which is conducive to forming a cooperative coalition.展开更多
Renewable energy has penetrated power grid enterprises on a large scale.Due to the intermittency and volatility of renewable energy generation,it is necessary to build new flexible grid-side resources to ensure the sa...Renewable energy has penetrated power grid enterprises on a large scale.Due to the intermittency and volatility of renewable energy generation,it is necessary to build new flexible grid-side resources to ensure the safe and stable operation of the power grid,which will cause great pressure on cost allocation for power grid enterprises.This article considers four types of flexible grid-side resources and constructs a dual-level configuration optimization model for flexible grid-side resources under the penetration of renewable energy.Based on the configuration results,the cost scale of flexible grid-side resources is estimated and an improved ancillary service cost allocation model based on the Shapley value method is proposed to smooth the allocation of ancillary service costs in the cost of flexible grid-side resources between the two main bodies of renewable energy and load.The calculation results show that,when the penetration rate of renewable-energy power is 30%and 35%,respectively,the cost of flexible grid-side resources is 9.606 billion yuan and 21.518 billion yuan,respectively.The proportion of ancillary service costs allocated to load is relatively high-about five times that of the ancillary service costs allocated to renewable energy-and the higher the penetration rate of renewable energy,the higher the proportion of ancillary service costs allocated to renewable energy.展开更多
The allocation of transmission cost provides important references and signals for system expansions and investments.This paper proposes a power tracing based equivalent bilateral exchange(PTEBX)method in which network...The allocation of transmission cost provides important references and signals for system expansions and investments.This paper proposes a power tracing based equivalent bilateral exchange(PTEBX)method in which network users are responsible for not only their induced power flows,but also power flows induced by whom they have equivalent bilateral exchanges with.The equivalent bilateral exchanges are recognized based on the power tracing.To evaluate the performance of different methods of allocating transmission cost,seven criteria are put forward that take into consideration characteristics of power systems.Theoretical analysis is then conducted to certify whether the methods satisfy the criteria.The results indicate that only the PTEBX method is able to satisfy all the seven criteria.Numerical examples based on the IEEE-30 system are presented to further demonstrate the applicability of the proposed method.展开更多
This paper presents a new solution to the problem of transmission cost allocation to its users.The proposed technique utilizes modified Z-bus theory,equivalent current injection and impedance of the generators and loa...This paper presents a new solution to the problem of transmission cost allocation to its users.The proposed technique utilizes modified Z-bus theory,equivalent current injection and impedance of the generators and loads,and is developed by the equal-sharing as well as the orthogonal projection principle.The procedure is performed in three steps.First,the modified Z-bus theory is used to calculate the contribution of the users into the network bus voltages as well as the branch currents.Then,the equal sharing principle is confirmed by the game theory solutions and is subsequently applied to identify the users’contributions into the branch power flows.After that,the orthogonal projections of the contributions are calculated and the concept of effective contributions is suggested.The proposed methodology provides the percentage shares of the users on the network complex variables,which help to better assess the contributions.A 2-bus and the IEEE 30-bus test system are used to validate the proposed technique.Finally,the proposed methodology is applied to the polish 2383-bus system to emphasize its applicability to large practical systems.展开更多
Under the seller's quantity discount, buyers self-organize or rely on a third party to aggregate their pur- chasing quantities to obtain lower prices. Because of the unequal member contributions in the cooperative...Under the seller's quantity discount, buyers self-organize or rely on a third party to aggregate their pur- chasing quantities to obtain lower prices. Because of the unequal member contributions in the cooperative pur- chasing organization, the buyers' strategy is diferent, the members often fluctuate, and the organizations do not sustain themselves. An efective mechanism is necessary to improve the performance of purchasing groups. We study the various forms of cost allocation mechanism in practice. Diferent allocation rules may have influence on the buyers' behavior(i.e., purchasing quantities, whether joining the organization or not). We analyze the serial cost allocation and equilibrium purchasing quantity based on a Nash equilibrium, and the results show that each buyer is worse of when not participating in the existence buying organization of the other buyers. We further find that the serial mechanism just confirms the most efcient Nash equilibrium: reasonable cost allocation rule is necessary for the subjects to identify their optimal strategy.展开更多
This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital cos...This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital costs fairly and reasonably among polluters in total emission control was analyzed. Then the possibility of applying game theory to the issue of the optimal capital cost allocation was expounded. Next the cooperative N person game model of the optimal capital cost allocation and its solution ways including method based on Shapley value, least core method, weak least core methods, proportional least core method, CGA method, MCRS method and so on were delineated. Finally through application of these methods it was concluded that to apply game theory in the optimal capital cost allocation issue is helpful to implement the total emission control planning schemes successfully, to control pollution effectively, and to ensure sustainable development.展开更多
This paper proposes a new method to allocate the transmission fixed costs among the network participants in a pool-based electricity market.The allocation process relies on the circuit laws,utilizes the modified imped...This paper proposes a new method to allocate the transmission fixed costs among the network participants in a pool-based electricity market.The allocation process relies on the circuit laws,utilizes the modified impedance matrix and is performed in two individual steps for the generators and loads.To determine the partial branch power flows due to the participants,the equal sharing principle is used and validated by the Shapley and Aumann-Shapley values as two preferred game-theoretic solutions.The proposed approach is also applied to determine the generators’contributions into the loads,and a new concept,named circuit-theory-based equivalent bilateral exchange(EBE),is introduced.Using the proposed method,fairly stable tariffs are provided for the participants.Cross-subsidies are reduced and a fair competition is made by the proposed method due to the counter-flows being alleviated compared with the well-known Z-bus method.Numerical results are reported and discussed to validate the proposed cost allocation method.Comparative analysis reveals that the method satisfies all conditions desired in a fair and efficient cost allocation method.Finally,the developed technique has been implemented successfully on the 2383-bus Polish power system to emphasize that the method is applicable to very large systems.展开更多
The issue of water scarcity highlights the importance of watershed management. A sound watershed manage- ment should make all water users share the incurred cost. This study analyzes the optimal allocation of watershe...The issue of water scarcity highlights the importance of watershed management. A sound watershed manage- ment should make all water users share the incurred cost. This study analyzes the optimal allocation of watershed management cost among different water users. As a consumable, water should be allocated to different users the amounts in which their marginal utilities (MUs) or marginal products (MPs) of water are equal. The value of MUs or MPs equals the water price that the watershed manager charges. When water is simultaneously used as consumable and non- consumable, the watershed manager produces the quantity of water in which the sum of MUs and/or MPs for the two types of uses equals the marginal cost of water production. Each water user should share the portion of watershed management cost in the percentage that his MU or MP accounts for the sum of MUs and/or MPs. Thus, the price of consumable water does not equal the marginal cost of water production even if there is no public good.展开更多
Routing, modulation and spectrum allocation in elastic optical networks is a problem aiming at increasing the capacity of the network. Many algorithms such as shortest path algorithm can be used as the routing section...Routing, modulation and spectrum allocation in elastic optical networks is a problem aiming at increasing the capacity of the network. Many algorithms such as shortest path algorithm can be used as the routing section of this problem. The efficiency of these algorithms is partly based on how the cost of each link is defined. In this study, we considered several basic metrics in cost of network links and compared their effects on the network capacity. In particular, the static costs and the dynamic costs were evaluated and compared. For dynamic scenarios, compared to static scenarios, at least one additional factor, the usage of the links, was added. We further considered a new factor that is based on probability of accommodating the signal at a given time in any given link. The results show that, among them, the shortest path algorithm provides the least blocking probability when the cost is a combination of link length and the abovementioned possibility/usage of the link.展开更多
To meet the booming development of diversified services and new applications in the future, the fifth-generation mobile conmmnication system (5G) has arisen. Resources are increasingly scarce in the @namic time-vary...To meet the booming development of diversified services and new applications in the future, the fifth-generation mobile conmmnication system (5G) has arisen. Resources are increasingly scarce in the @namic time-varying of 5G networks. Allocating resources effectively and ensuring quality of service (QoS) requirements of multi-seiwices come to be a research focus. In this paper, we utilize effective capacity to build a utility function with multi-QoS metrics, including rate, delay bound and packet loss ratio. Taking advantage of opportunity cost (OC), we also propose a multi-QoS guaranteed resource allocation algm'ithm for multi-services to consider the future condition of system. In the algorithm, according to different business characteristics and the theory of OC, we propose different selection conditions for QoS users and best effort (BE) users to choose more reasonable resources. Finally, simulation results show that our proposed algorithm achieves superior system utility and relatively better fairness in multi-service scenarios.展开更多
Congestion management in an electricity market is introduced in this paper and a new method of allocating congestion cost to transactions is proposed. The proposed method is a two-step process, in which the total cong...Congestion management in an electricity market is introduced in this paper and a new method of allocating congestion cost to transactions is proposed. The proposed method is a two-step process, in which the total congestion cost is firstly allocated to congested facilities and then to each transaction involved. The cost of relieving a congested facility allocated to each transaction is proportional to the power flow change on the congested facility caused by the transaction. The more the power flow change is on the congested facility caused by the transaction, the deeper the degree of involvement by the transaction. Therefore, cutting down the magnitudes of such transactions contributes to relieving congestion. Test results on a 5-bus system indicate that the proposed method can reflect reasonably the degree of involvement by each transaction in the congestion and provide correct price signals contributing to relieving congestion.展开更多
Based on the concepts of objective fact and subjective desire proposed in this paper, the problems that exist in the nodal injections-based and transaction-based transmission service allocation scheme are pointed out....Based on the concepts of objective fact and subjective desire proposed in this paper, the problems that exist in the nodal injections-based and transaction-based transmission service allocation scheme are pointed out. To get around the problems above, a novel transmission service allocation scheme is proposed which considers the power flow distribution and the transaction impact on the system simultaneously so that the issues of “Cross-subsidies” and “Counter flow” can be avoided. The principle of the scheme is illustrated using two simple networks with 7 cases. The results show that the proposed scheme can satisfy the properties necessary for the development and growth of the electricity market.展开更多
In the electricity market, charging based on the traditional spot electricity price often results in the payment imbalance of electric network, and goes against the development of the power system. So, it is necessary...In the electricity market, charging based on the traditional spot electricity price often results in the payment imbalance of electric network, and goes against the development of the power system. So, it is necessary to modify the spot price. The key of the modification lies in how to calculate the fixed unit transmission cost of each node, that is how to allocate the fixed transmission cost to users.To solve this problem, we develop a power flow tracing algrithm to modify the spot price. We put forward a path searching method based on the graph theory after studying the fundamental principle of power flow tracing and apply the method to the downstream tracing algorithm and upstream tracing algorithm according to the proportional distribution principle. Furthermore, to improve the computational efficiency of the algorithm, we introduce the branch expunction method to optimize the node order. By using the result of power flow tracing to get fixed node transmission cost and introducing it to modify the spot price, we obtain the synthetical price.The application to a 5-bus system prove the algorithm feasible.展开更多
An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method,a manufacturing difficulty coeffic...An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method,a manufacturing difficulty coefficient is derived,which takes into account of several factors affecting the manufacturing cost,including the forming means of the blank,size,machining surface features,operator’s skills and machinability of materials. The coefficient is then converted into a weight factor used in the inversed square model representing the relationship between the cost and tolerance,and,hence,an objective function for cost is established in optimizing and allocating tolerance. The higher is the manufacturing difficulty coefficient,the higher is the relative manufacturing cost and the higher is the weight factor of the tolerance allocation,which indicates the increase of the tolerance’s effects on the total manufacturing cost and,therefore,a larger tolerance should be allocated. The computer-aided tolerance allocation utilizing this model makes it more convenient,accurate and practicable.展开更多
Distributed photovoltaic(PV)systems have constantly been the key to achieve a low-carbon economy in China.However,the development of Chinese distributed PV systems has failed to meet expectations because of their irra...Distributed photovoltaic(PV)systems have constantly been the key to achieve a low-carbon economy in China.However,the development of Chinese distributed PV systems has failed to meet expectations because of their irrational profit and cost allocations.In this study,the methodology for calculating the levelized cost of energy(LCOE)for PV is thoroughly discussed to address this issue.A mixed-integer linear programming model is built to determine the optimal system operation strategy with a benefit analysis.An externality-corrected mathematical model based on Shapley value is established to allocate the cost of distributed PV systems in 15 Chinese cities between the government,utility grid and residents.Results show that(i)an inverse relationship exists between the LCOEs and solar radiation levels;(ii)the government and residents gain extra benefits from the utility grid through net metering policies,and the utility grid should be the highly subsidized participant;(iii)the percentage of cost assigned to the utility grid and government should increase with the expansion of battery bank to weaken the impact of demand response on increasing theoretical subsidies;and(iv)apart from the LCOE,the local residential electricity prices remarkably impact the subsidy calculation results.展开更多
文摘With maturing deregulated environment for electricity market, cost of transmission congestion becomes a major issue for power system operation. Uniform Marginal Price and Locational Marginal Price (LMP) are the two practical pricing schemes on energy pricing and congestion cost allocation, which are based on different mechanisms. In this paper, these two pricing schemes are introduced in detail respectively. Also, the modified IEEE-14-bus system is used as a test system to calculate the allocated congestion cost by using these two pricing schemes.
基金The National Natural Science Foundation of China(No.71531004).
文摘To encourage retailers to form cooperative alliances to jointly replenish inventory,considering that the supplier provides a flexible lead time and quantity discount to retailers,a model of average total cost per unit time of periodic joint replenishment is constructed,and an approximate algorithm,which can satisfy the requirement of any given precision,is given.The cost allocation rule in the core of the joint replenishment game is designed based on the cooperative game theory.The numerical experiment results show that the proposed algorithm can quickly solve the joint replenishment problem when the item number is not greater than 640.The retailer's cost saving rate is always greater than 0,and it increases with the increase in quantity discount and fixed cost after adopting the given cost allocation rule.With the increase in the safety stock level,the retailer's cost saving rate increases first and then decreases;and the retailer's cost saving rate increases with the increase in the size of the alliance,but it decreases as the number of product category increases.The proposed cost allocation rule can reduce the retailer's cost up to 20%,which is conducive to forming a cooperative coalition.
基金funded by the Science and Technology Project of State Grid Ningxia Electric Power Co.,Ltd(Research on the influence analysis model of multidimensional penetration mode of new energy on incremental cost of power grid and electricity price grooming mechanism,5229JY230006).
文摘Renewable energy has penetrated power grid enterprises on a large scale.Due to the intermittency and volatility of renewable energy generation,it is necessary to build new flexible grid-side resources to ensure the safe and stable operation of the power grid,which will cause great pressure on cost allocation for power grid enterprises.This article considers four types of flexible grid-side resources and constructs a dual-level configuration optimization model for flexible grid-side resources under the penetration of renewable energy.Based on the configuration results,the cost scale of flexible grid-side resources is estimated and an improved ancillary service cost allocation model based on the Shapley value method is proposed to smooth the allocation of ancillary service costs in the cost of flexible grid-side resources between the two main bodies of renewable energy and load.The calculation results show that,when the penetration rate of renewable-energy power is 30%and 35%,respectively,the cost of flexible grid-side resources is 9.606 billion yuan and 21.518 billion yuan,respectively.The proportion of ancillary service costs allocated to load is relatively high-about five times that of the ancillary service costs allocated to renewable energy-and the higher the penetration rate of renewable energy,the higher the proportion of ancillary service costs allocated to renewable energy.
基金supported by the Management Consulting Program of the State Grid Corporation of China under Grant SGTYHT/15-WT-218.
文摘The allocation of transmission cost provides important references and signals for system expansions and investments.This paper proposes a power tracing based equivalent bilateral exchange(PTEBX)method in which network users are responsible for not only their induced power flows,but also power flows induced by whom they have equivalent bilateral exchanges with.The equivalent bilateral exchanges are recognized based on the power tracing.To evaluate the performance of different methods of allocating transmission cost,seven criteria are put forward that take into consideration characteristics of power systems.Theoretical analysis is then conducted to certify whether the methods satisfy the criteria.The results indicate that only the PTEBX method is able to satisfy all the seven criteria.Numerical examples based on the IEEE-30 system are presented to further demonstrate the applicability of the proposed method.
文摘This paper presents a new solution to the problem of transmission cost allocation to its users.The proposed technique utilizes modified Z-bus theory,equivalent current injection and impedance of the generators and loads,and is developed by the equal-sharing as well as the orthogonal projection principle.The procedure is performed in three steps.First,the modified Z-bus theory is used to calculate the contribution of the users into the network bus voltages as well as the branch currents.Then,the equal sharing principle is confirmed by the game theory solutions and is subsequently applied to identify the users’contributions into the branch power flows.After that,the orthogonal projections of the contributions are calculated and the concept of effective contributions is suggested.The proposed methodology provides the percentage shares of the users on the network complex variables,which help to better assess the contributions.A 2-bus and the IEEE 30-bus test system are used to validate the proposed technique.Finally,the proposed methodology is applied to the polish 2383-bus system to emphasize its applicability to large practical systems.
基金the National Natural Science Foundation of China(No.70932004)the Social Science Foun-dation of China(No.11&ZD174)the Foundation of Humanities and Social Sciences in Universities of Shandong(No.J13WG68)
文摘Under the seller's quantity discount, buyers self-organize or rely on a third party to aggregate their pur- chasing quantities to obtain lower prices. Because of the unequal member contributions in the cooperative pur- chasing organization, the buyers' strategy is diferent, the members often fluctuate, and the organizations do not sustain themselves. An efective mechanism is necessary to improve the performance of purchasing groups. We study the various forms of cost allocation mechanism in practice. Diferent allocation rules may have influence on the buyers' behavior(i.e., purchasing quantities, whether joining the organization or not). We analyze the serial cost allocation and equilibrium purchasing quantity based on a Nash equilibrium, and the results show that each buyer is worse of when not participating in the existence buying organization of the other buyers. We further find that the serial mechanism just confirms the most efcient Nash equilibrium: reasonable cost allocation rule is necessary for the subjects to identify their optimal strategy.
文摘This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital costs fairly and reasonably among polluters in total emission control was analyzed. Then the possibility of applying game theory to the issue of the optimal capital cost allocation was expounded. Next the cooperative N person game model of the optimal capital cost allocation and its solution ways including method based on Shapley value, least core method, weak least core methods, proportional least core method, CGA method, MCRS method and so on were delineated. Finally through application of these methods it was concluded that to apply game theory in the optimal capital cost allocation issue is helpful to implement the total emission control planning schemes successfully, to control pollution effectively, and to ensure sustainable development.
文摘This paper proposes a new method to allocate the transmission fixed costs among the network participants in a pool-based electricity market.The allocation process relies on the circuit laws,utilizes the modified impedance matrix and is performed in two individual steps for the generators and loads.To determine the partial branch power flows due to the participants,the equal sharing principle is used and validated by the Shapley and Aumann-Shapley values as two preferred game-theoretic solutions.The proposed approach is also applied to determine the generators’contributions into the loads,and a new concept,named circuit-theory-based equivalent bilateral exchange(EBE),is introduced.Using the proposed method,fairly stable tariffs are provided for the participants.Cross-subsidies are reduced and a fair competition is made by the proposed method due to the counter-flows being alleviated compared with the well-known Z-bus method.Numerical results are reported and discussed to validate the proposed cost allocation method.Comparative analysis reveals that the method satisfies all conditions desired in a fair and efficient cost allocation method.Finally,the developed technique has been implemented successfully on the 2383-bus Polish power system to emphasize that the method is applicable to very large systems.
文摘The issue of water scarcity highlights the importance of watershed management. A sound watershed manage- ment should make all water users share the incurred cost. This study analyzes the optimal allocation of watershed management cost among different water users. As a consumable, water should be allocated to different users the amounts in which their marginal utilities (MUs) or marginal products (MPs) of water are equal. The value of MUs or MPs equals the water price that the watershed manager charges. When water is simultaneously used as consumable and non- consumable, the watershed manager produces the quantity of water in which the sum of MUs and/or MPs for the two types of uses equals the marginal cost of water production. Each water user should share the portion of watershed management cost in the percentage that his MU or MP accounts for the sum of MUs and/or MPs. Thus, the price of consumable water does not equal the marginal cost of water production even if there is no public good.
文摘Routing, modulation and spectrum allocation in elastic optical networks is a problem aiming at increasing the capacity of the network. Many algorithms such as shortest path algorithm can be used as the routing section of this problem. The efficiency of these algorithms is partly based on how the cost of each link is defined. In this study, we considered several basic metrics in cost of network links and compared their effects on the network capacity. In particular, the static costs and the dynamic costs were evaluated and compared. For dynamic scenarios, compared to static scenarios, at least one additional factor, the usage of the links, was added. We further considered a new factor that is based on probability of accommodating the signal at a given time in any given link. The results show that, among them, the shortest path algorithm provides the least blocking probability when the cost is a combination of link length and the abovementioned possibility/usage of the link.
基金supported by the National Science and Technology Major Project under Grant No.2016ZX03001009-003the Nature and Science Foundation of China under Grants Nos.61471068111 Project of China B16006
文摘To meet the booming development of diversified services and new applications in the future, the fifth-generation mobile conmmnication system (5G) has arisen. Resources are increasingly scarce in the @namic time-varying of 5G networks. Allocating resources effectively and ensuring quality of service (QoS) requirements of multi-seiwices come to be a research focus. In this paper, we utilize effective capacity to build a utility function with multi-QoS metrics, including rate, delay bound and packet loss ratio. Taking advantage of opportunity cost (OC), we also propose a multi-QoS guaranteed resource allocation algm'ithm for multi-services to consider the future condition of system. In the algorithm, according to different business characteristics and the theory of OC, we propose different selection conditions for QoS users and best effort (BE) users to choose more reasonable resources. Finally, simulation results show that our proposed algorithm achieves superior system utility and relatively better fairness in multi-service scenarios.
文摘Congestion management in an electricity market is introduced in this paper and a new method of allocating congestion cost to transactions is proposed. The proposed method is a two-step process, in which the total congestion cost is firstly allocated to congested facilities and then to each transaction involved. The cost of relieving a congested facility allocated to each transaction is proportional to the power flow change on the congested facility caused by the transaction. The more the power flow change is on the congested facility caused by the transaction, the deeper the degree of involvement by the transaction. Therefore, cutting down the magnitudes of such transactions contributes to relieving congestion. Test results on a 5-bus system indicate that the proposed method can reflect reasonably the degree of involvement by each transaction in the congestion and provide correct price signals contributing to relieving congestion.
文摘Based on the concepts of objective fact and subjective desire proposed in this paper, the problems that exist in the nodal injections-based and transaction-based transmission service allocation scheme are pointed out. To get around the problems above, a novel transmission service allocation scheme is proposed which considers the power flow distribution and the transaction impact on the system simultaneously so that the issues of “Cross-subsidies” and “Counter flow” can be avoided. The principle of the scheme is illustrated using two simple networks with 7 cases. The results show that the proposed scheme can satisfy the properties necessary for the development and growth of the electricity market.
文摘In the electricity market, charging based on the traditional spot electricity price often results in the payment imbalance of electric network, and goes against the development of the power system. So, it is necessary to modify the spot price. The key of the modification lies in how to calculate the fixed unit transmission cost of each node, that is how to allocate the fixed transmission cost to users.To solve this problem, we develop a power flow tracing algrithm to modify the spot price. We put forward a path searching method based on the graph theory after studying the fundamental principle of power flow tracing and apply the method to the downstream tracing algorithm and upstream tracing algorithm according to the proportional distribution principle. Furthermore, to improve the computational efficiency of the algorithm, we introduce the branch expunction method to optimize the node order. By using the result of power flow tracing to get fixed node transmission cost and introducing it to modify the spot price, we obtain the synthetical price.The application to a 5-bus system prove the algorithm feasible.
文摘An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method,a manufacturing difficulty coefficient is derived,which takes into account of several factors affecting the manufacturing cost,including the forming means of the blank,size,machining surface features,operator’s skills and machinability of materials. The coefficient is then converted into a weight factor used in the inversed square model representing the relationship between the cost and tolerance,and,hence,an objective function for cost is established in optimizing and allocating tolerance. The higher is the manufacturing difficulty coefficient,the higher is the relative manufacturing cost and the higher is the weight factor of the tolerance allocation,which indicates the increase of the tolerance’s effects on the total manufacturing cost and,therefore,a larger tolerance should be allocated. The computer-aided tolerance allocation utilizing this model makes it more convenient,accurate and practicable.
基金This study was sponsored by the National Key R&D Program of China(Grant No.2018YFD1100202)China Postdoctoral Science Foundation(Grant No.2018M643807XB)and Education Department of Shaanxi(Grant No.19JS041).
文摘Distributed photovoltaic(PV)systems have constantly been the key to achieve a low-carbon economy in China.However,the development of Chinese distributed PV systems has failed to meet expectations because of their irrational profit and cost allocations.In this study,the methodology for calculating the levelized cost of energy(LCOE)for PV is thoroughly discussed to address this issue.A mixed-integer linear programming model is built to determine the optimal system operation strategy with a benefit analysis.An externality-corrected mathematical model based on Shapley value is established to allocate the cost of distributed PV systems in 15 Chinese cities between the government,utility grid and residents.Results show that(i)an inverse relationship exists between the LCOEs and solar radiation levels;(ii)the government and residents gain extra benefits from the utility grid through net metering policies,and the utility grid should be the highly subsidized participant;(iii)the percentage of cost assigned to the utility grid and government should increase with the expansion of battery bank to weaken the impact of demand response on increasing theoretical subsidies;and(iv)apart from the LCOE,the local residential electricity prices remarkably impact the subsidy calculation results.