Transmission Cost Allocation Research Articles

Distribution grid reconfiguration sensitive to transmission cost allocation

AbstractThe reconfiguration of electrical distribution systems has been addressed in numerous scientific studies. Thus, several techniques and models are considered, especially to reduce electrical losses and improve the voltage profile. However, it is clear that even with the increase in research, which has been accentuated since the last decade, the locational pricing and the transmission costs allocation is little explored. In this regard, the proposed method is a distribution system reconfiguration (DSR) optimization problem focused on minimizing the use of the transmission system. In order to validate the meta‐heuristic employed for the DSR, the IEEE 33 and 69 node test systems are used as a proof of concept. In addition, case studies with four substations, three different transmission cost allocation techniques, and transmission system capacity scenarios are analyzed. Numerical results showed an important transmission expansion deferral with consequent decrease in overall costs compared to the classic DSR. The transmission network use of system (TNUoS) charges can play a crucial role in reducing the total cost of the electrical system, promoting distributors to change their feeder patterns so that a larger share of loads access substations with lower charges.

Improving of Transmission Cost Allocation Method to Accelerate the Investment Recovery for Transmission lines in Deregulated Power System

Improving of Transmission Cost Allocation Method to Accelerate the Investment Recovery for Transmission lines in Deregulated Power System

Transmission Pricing Dynamically Integrated with Distribution Planning

Modern electrical networks with automatic control devices and with models that look for minimizing their costs will naturally increase the loading on buses with lower tariffs. We can identify two factors that are contributing to accelerate the network modernization. Firstly, the global targets to reduce the emission of polluting gases, which are boosting the transport electrification, a highly dynamic element. Secondly, the greater participation of clients in decision-making processes due to advances in means of measurement and communication. In this context, the article brings two innovative and direct contributions. The integration of transmission and distribution segments in a unique set of simulation, and the proposal of a novel transmission cost allocation (TCA) methodology. The integration between both segments confirms that loads responsive to tariff signals will seek buses with lower tariffs. The results show that traditional TCA methods do not respond to load variations in a coordinated manner. Therefore, the main contribution of the proposed methodology is to capture the consumption dynamics and make tariff adjustments proportional to the load variations. It preserves the tariff characteristics of traditional TCA methods and automatically induces a dynamic tariff-load balance for the entire power system. Thus, new investments in network reinforcements can be postponed, reducing the total cost paid by users in a long-term prospect.

Cross-Regional Transaction Path Configuration of Renewable Energy Resources by Graph Theory-Based Transmission Cost Allocation Method

For the transaction path configuration of renewable energy cross-regional consumption, there are several critical problems such as the key node identification, the maximum delivery quota, and the transmission cost allocation (TCA). To solve these problems, firstly, the simplified graph model of the ultra-high-voltage (UHV) network is constructed, and the network connectivity and the vulnerability of the key nodes are analyzed from the perspective of the system topology. Secondly, the source and sink nodes are set corresponding to the electricity seller and buyer in the power market, and the Edmonds–Karp algorithm is utilized to search for the augmenting path. Also, the maximum transmission quota of the transaction path is achieved effectively and rapidly. Finally, the social welfare is set as the optimization objective, and the optimal allocation of multiple power flows in multiple feasible transaction paths is carried out. The case study was conducted based on the 17 cross-regional transactions in China including the typical Gansu-Shanghai renewable energy consumption case. Compared to the existing TCA method, the simulation result shows that the proposed method can effectively utilize the transmission potential, decrease the overall transmission cost, and provide proper economic signals.

A new benefit-based transmission cost allocation scheme based on capacity usage differentiation

This paper proposes a new transmission cost allocation (TCA) scheme, which includes two parts. The first part deals with identifying the transmission capacity that should be allocated. In this section, a novel scheme is introduced, which determines the beneficial capacity based on various operation conditions over the period, during which the transmission capacity is expected to be fully used. Then, only the cost of the beneficial capacity rather than total transmission capacity is allocated to users. This approach towards TCA brings about important advantages: it promotes transmission sustainability and incentivizes more transmission investments while encouraging users to utilize transmission systems optimally and preventing transmission owners from overinvesting. The second part proposes a new benefit-based algorithm for TCA. This algorithm enjoys significant benefits over existing benefit-based methods: none of the current benefit-based TCA procedures can always generate allocation factors, making them impractical, but the proposed method allocates transmission costs in any transmission network, so it can be applied to real systems. Additionally, unlike the existing benefit-based approaches, the proposed method allocates transmission costs by considering users' benefits of the entire beneficial capacity rather than a minor fraction of it. Numerical examples demonstrate the applicability and validity of the proposed TCA scheme.

Novel dynamic framework to form transmission tariffs with suitable economic signals

The energy transition intensifies the limitations verified on transmission cost allocation (TCA) methods traditionally employed. Two methodological limitations common to them can be identified: (1) lack of coordination between transmission pricing and load evolution and (2) lack of signals to guide the growth in generation capacity. This work presents a novel dynamic framework to form transmission tariffs capturing two important aspects: the load evolution at each bus and the optimal generation necessary to minimize the transmission loss. The framework overcomes the identified limitations and provides suitable tariff adjustments that reflect the responsibility of each user on network investment. A dynamic tariff-load balance is induced and generators who contribute to loss minimization are rewarded. So, effective signals for the generation capacity expansion are obtained. Also, the tariff formation is integrated with the reconfiguration of responsive distribution networks (DNs). Thus, this work proposes a new structure in terms of tariff integration and operational coordination in accordance with modern rate designs and recent energy security concerns.

Power Distribution Network Reconfiguration Considering the Transmission System Usage

This paper presents a heuristic reconfiguration algorithm, considering the locational economic signals of the tariffs for the use of the transmission system. Among other aspects, the economic signaling of locational tariffs encourages the rationalization of the use of transmission assets, as well as the reduction of operating costs. Therefore, the proposed algorithm is presented as an optimization problem with a focus on minimizing the transmission system usage. In order to validate the efficiency of the proposed reconfiguration algorithm, the IEEE 33 and 69 nodes test systems are evaluated. In addition, the algorithm is tested for different transmission cost allocation techniques and transmission system capacity scenarios. The results achieved demonstrate the systemic rationalization of the use of assets, which characterize the proposed algorithm as an important tool to avoid the increase in the share of energy transport in the tariff for the final consumer.

Hierarchical collaborative expansion planning for transmission and distribution networks considering transmission cost allocation

Expansion planning for transmission networks and distribution networks has been widely investigated. For those entities that manage transmission and distribution assets, it is essential to develop a collaborative plan for both networks under coupling constraints, such as a total budget limitation constraint. Here, two technical issues should be considered: the high complexity of the integrated planning model due to the coupling of transmission and distribution networks and the inefficient allocation of the transmission cost (which is a major part of the total fixed cost of power systems). Based on an equivalent model of distribution network expansion planning proposed in our previous work, this paper designs a hierarchical collaborative expansion planning framework for transmission and distribution networks that efficiently allocates the transmission cost. Formulations of a conventional integrated model and the proposed hierarchical model are compared to show how the equivalent model of the distribution network can reduce the model’s complexity. Case studies conducted on both a small-scale case (Garver’s 6-bus system) and a large-scale case (IEEE 118-Bus system) demonstrate the effectiveness of the proposed framework by approximately decomposing the complex integrated planning model into several small-scale tractable models with high accuracy. Case studies also indicate that considering the transmission cost allocation in the electricity prices during collaborative expansion planning will decrease the total planning and operating costs.

Performance analysis of hybrid techniques for evaluation of power transmission cost and loss allocation based on transmission reliability margin

Performance analysis of hybrid techniques for evaluation of power transmission cost and loss allocation based on transmission reliability margin

Selection of Cost Allocation Methods for Power Grid Enterprises Based on Entropy Weight Method

With the liberalization of the electricity trading market, market participants pay more attention to the fair and reasonable distribution of relevant costs. However, the traditional transmission and distribution cost allocation methods based on fixed costs have serious cross-subsidies. In this context, a variety of methods for amortizing transmission and distribution costs from different angles have emerged, but these methods generally have some shortcomings, such as excessive calculations. To select the optimal cost allocation method objectively and rationally, this paper uses the entropy weight method to evaluate different cost allocation methods based on four indicators: comprehensibility, application difficulty, load change reflection ability, and transmission stability. Studies have shown that the hybrid transmission and distribution cost allocation method combining the stamp method and the peak liability method is more reasonable and effective.

Re-dispatch and Application of FACTs for Transactions Allocation in Deregulated Electricity Markets

In the current scenario, transmission cost allocation is one of the significant difficulties arises due to the expansion in power exchanges in transmission open access looked by electric energy area. The proposed method calculates transmission cost allocation by considering bilateral & multilateral transactions. The transmission cost allocation approach in the proposed method derives from equivalent bilateral which states that a small amount of every generator provides with each request in consistently and separated manner. The influence of power flow in network via all lines due to a transaction is measured by power flow solution. This paper discusses the congestion problem in the deregulated electricity market using an optimal power flow (OPF). The transmission lines are uncongested using re-dispatch method and then taxes are calculated for the establishment of the flexible A.C. transmission systems (FACTS) devices in the transmission network to reduce taxes. The excellent location of FACTS device can be identified by the bus on which highest T. The result indicates that the combination of TCSC and SVC incredibly discount the measure of re-dispatched power which provides optimal operating point nearer to the market settlement. Hence, TCSC and SVC gives convenient option to block the execution of transmission estimation utilizing approaches and calculate the transmission price.

Comparison of cost allocation models for transmission and distribution by voltage levels based on postage stamp method and peak load liability method

In order to make the allocation of transmission and distribution costs more reasonable, the cost allocation models for transmission and distribution of different voltage levels based on postage stamp method and peak load liability method are constructed. Two models are used to calculate and compare the transmission and distribution costs of different voltage levels in a power grid company. The results show that the peak load liability method is more reasonable than the stamp method to allocate transmission and distribution costs among different voltage levels.

Power Flow Tracing for Active Congestion Management in Modern Power Systems

Future power systems will be based on the more active role of distribution system and its cooperation with transmission system. The main issue, which will appear in the network, is the congestion. Congestion management will become one of the crucial elements of power system operation since Distributed Energy Resources (DERs) will be playing a more important role in power systems. Moreover, the evolution also changed the character of the systems to be more dynamic—the need for precise description of power flow and shares of particular nodes in line flows will emerge. This paper presents the potential solution to the congestion management problem by using the active role of the distribution system, which may dismantle the congestions by offering flexibility services. The tools which will be indispensable in this process will be Power Flow Tracing (PFT) methods. The main goal of this paper is to present modification of PFT method and its possible applications. The correctness of the Modified Inage Domain (MID) method is verified. The identification, verification and possible applications of the new MID method are also shown in the paper. It has been proven that the new method may be used in applications of allocation of transmission cost and in application in modern power systems for advanced congestion management.

Objective transmission cost allocation based on marginal usage of power network in spot market

Transmission cost allocation is important for a liberalized market with open access to transmission facilities. However, it remains controversial how to objectively allocate the transmission costs because there is no unique answer for the mapping between the power injections at buses and the power flows on branches. However, the marginal usage of the power network can be uniquely determined according to the market-clearing solution. In this paper, an objective transmission cost allocation method is proposed based on the marginal usage of the power network. The influence of the loss modeling on the proposed method is discussed. The “extent of use” of transmission facilities is determined based on the economic principles without subjective assumptions, which obeys the fairness requirement of spot markets. The proposed method is computationally efficient, in which only matrix manipulations are involved. Moreover, the proposed approach is compatible with the standards and procedures of the current spot market operation in the U.S., China, and many other countries and holds promise for industrial applications.

Analysis of Transmission Cost Allocation Strategies with Reliability for Deregulated Systems

This paper presents a learning review of various strategies related to the improvement of the reliability for the deregulated system, for instance, Genetic Algorithms (GA), Tabu Search (TS), heuristic calculations and system based techniques. These methodologies were produced for advancing reliability as either software or hardware exclusively. Besides, the cost segments related with limit utilize and reliability advantage charges are resolved and various optimization techniques are acknowledged of action of the goal work

Electricity transmission cost allocation and network efficiency: Implications for Mexico's liberalized power market

In liberalized electricity markets, the coordination and funding of transmission infrastructure are ongoing challenges. The challenge is to establish transmission tariffs that provide signals for efficient usage of the existing network and demand for new network capacity. Mexico's liberalized electricity market exemplifies the changing responsibilities in transmission planning. Through the adoption of locational marginal pricing, the Mexican market is well positioned to capture congestion costs and motivate efficient behavior. We highlight some of the potential problems that Mexico's currently planned approach and transmission tariffs could raise for generation location incentives. A long-term transmission plan can facilitate network optimization, with generation following the lead of transmission investment instead of the other way around.

Development of a circuit-theory based transmission cost allocation method by orthogonal projection and equal-sharing principles

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.

Fixed Transmission Cost Allocation Based on a Nucleolus Solution with Economic Incentive on Power Market

The economic incentive of fixed transmission cost under power market is investigated in this paper. The fixed transmission cost allocation based on cooperate game model gives the economic signals of the difference of loads, which stimulates the customers to choose the reasonable way to get the power. The nucleolus is the only one solution with character of exit and unique in all cooperate game solution. The fixed transmission cost is allocated to each customer according to the nucleolus. The economic attribute of nucleolus also determines the responsibility of customers for the allocation. What is more, the fixed transmission cost allocated to one customer will change if different generator is chosen to supply power to this customer. So customers choose the generators economically and reasonably. The effectiveness of the economic stimulation based on the nucleolus solution for fixed transmission cost allocation is verified by the 5-bus system.

Correction to: Usage Based Transmission Cost Allocation to Wheeling Transactions in Bilateral Markets

The original version of this article unfortunately contained a mistake in the second author name.

Tri-Level Expansion Planning for Transmission Networks and Distributed Energy Resources Considering Transmission Cost Allocation

A well-designed transmission cost allocation (TCA) scheme should reveal energy users’ actual usage of transmission assets. By investing in distributed energy resources (DERs), a user should be allocated with a lower transmission price if devoted to reducing transmission capacity usage. To evaluate the impacts of TCA, a coplanning framework for centralized transmission networks and DERs is developed in this paper. Distinguished from the existing literature, we consider hourly transmission prices (TPs) that are updated by power flow tracing, together with locational marginal prices (LMPs) to incentivize users’ investments for DERs. This problem is formulated as a tri-level model. On the first level, transmission expansion planning is optimized to satisfy transmission capacity requirements. On the second level, given the hourly LMPs and TPs, users at different buses strategically invest in DERs. On the third level, the market is cleared, and LMPs and TPs are updated. The lower two levels form a market equilibrium problem that can be solved by a diagonalization method. An iterative algorithm is proposed to solve the tri-level model, and convergence analysis is conducted. Case studies based on a modified Garver's 6-bus system and the IEEE 118-bus system demonstrate that a well-designed TCA scheme can incentivize users to invest in DERs, which effectively defers transmission expansion and reduces the system-wide investment costs.