A Loss Allocation Mechanism for Power System Transactions

International Journal of Electrical Power & Energy Systems, 2007

This paper presents an optimal power flow formulation in which the generation is dispatched in order to compensate for losses allocated to different transactions. Since the loss allocation itself depends on the solution, the two problems are combined and solved together. Loss allocation scheme developed by the authors earlier [Ding Q, Abur A. Transmission loss allocation in a multiple-transaction framework, IEEE Trans Power Syst 2004;19(1):214-20] is used in this formulation. It is assumed that each transaction is entitled to select its own designated generators to compensate for its allocated losses. The case where some transactions prefer instead to let the independent system operator (ISO) to provide the loss compensation service is also considered. An optimization procedure, which yields the least-cost compensation from participating generators, is developed for this purpose by using an OPF model. Several numerical examples are included to demonstrate the proposed procedures.

IEEE Transactions on Power Systems, 1999

This paper presents a powerflow based method for an accurate assessment of the impact of a transaction on a n area/utility. The method determines for each transaction the following: the flowpath of the transaction (both real and reactive power components), generator reactive power support from each area/utility, and real power loss support from each area/utility. The proposed method is tested extensively on a real-life system. Results indicate that the method is very accurate in allocating the above transmission services on a transaction basis.

IEEE Transactions on Power Systems, 2000

A physical-flow-based approach to allocating transmission losses in a multiple-transaction system is presented. The allocation scheme is developed using a framework in which the transactions are explicitly represented. The proposed scheme is based on expressing losses explicitly in terms of all the transactions in the system. An important property of the allocation scheme is its effective capability to deal with counter flows that result in the presence of specific transactions. Extensive numerical testing indicates that the allocation scheme produces loss allocations that are appropriate and that behave in a physically reasonable manner. Test results on several systems are presented.

IEE Proceedings - Generation, Transmission and Distribution, 2006

The paper addresses the issue of apportioning of the cost of transmission losses to generators and demands in a multimarket framework. Line flows are unbundled using equivalent bilateral exchanges on a DC-network model and allocated to generators and demands. Losses are then calculated based on unbundled flows and straightforwardly apportioned to generators and demands. The proposed technique is particularly useful in a multimarket framework, where all markets have a common grid operator with complete knowledge of all network data, as is the case of the Brazilian electric-energy system. The methodology proposed is illustrated using the IEEE Reliability Test System and compared numerically with an alternative technique. Appropriate conclusions are drawn.

Electric Power Systems Research, 2004

This paper presents a usage-based transmission cost allocation method based on a new set of line utility factors (LUFs), which provides power transaction impact on each element of the network in deregulated power system operation. The developed LUFs relates the line flows with generation/load for a given network configuration. In this paper, a bilateral transaction contract model through a transaction matrix and line utility factors are used to evaluate cost of bilateral power contracts. The proposed method allocates the transaction costs over the participants/contracts proportional to the ratio of power flow caused by each participant/contract and the total power flows on a designated transmission line. The method has been applied on a few sample systems, and the results for sample systems and a real life EHV equivalent system are presented for illustrative purposes. .in (D. Thukaram). the emerging multi-transaction operation accurately and efficiently is quite essential .

2010 7th International Conference on the European Energy Market, 2010

The possibility for market participants to place their bids in markets where they are not geographically located is investigated in this paper. An iterative procedure enabling the simultaneous clearing of those overlapping markets by transaction schedulers while managing the resulting pre and post-contingency congestion is proposed. Transmission losses are calculated during the iterations and are accounted for by allocating them to the various transaction schedulers. The procedure is illustrated and commented on a test system.

2007 IEEE Lausanne Power Tech, 2007

This paper presents a methodology for transmission loss allocation in pool markets, based on circuit laws, proportional sharing and superposition principles. The problem is divided in two parts: the first one considers the operation scenarios and the other the loads supply via transmission paths from generators. A five-bus system has been used to demonstrate and compare the performance of the proposed framework with results provided by previous works.

2004 International Conference on Power System Technology, 2004. PowerCon 2004., 2004

This paper presents a methodology based on the Kirchhoff's circuit laws, and transaction power flow analysis for unbundling and allocating transmission losses to the participants of a pool-based electricity markets. From a solved load flow and using the basic network equations and not make any simplifying assumptions a new, simples and transparent branch loss formula in injections currents terms of each bus or market participant is derived. It natural separation explicitly expresses the loss allocation at each system branch pertaining to individual bus or market participant. Then, the proposed methodology provides branch unbundling and nodal allocating of transmission losses among power market participants. Extensions and strategies considering unsubsidized loss allocation and loss allocation based on a predefined proportion are also included. Several important aspects related with the allocation fairness and transparency are illustrated and compared by numerical applications with a 4-bus system. Index Terms-Loss allocation, pool-based electricity markets, power flow, transmission losses, transmission open access.

TELKOMNIKA Telecommunication Computing Electronics and Control, 2020

One of the trends in electricity reform is the involvement of bilateral contracts that will participate in electricity business development. Bilateral agreements require fair transmission loss costs compared with the integrated power system. This paper proposes a new algorithm in determining the optimal allocation of transmission loss costs for bilateral contracts based on the direct method in economic load dispatch. The calculation for an optimal power flow applies fast decoupled methods. At the same time, the determination of a fair allocation of transmission losses uses the decomposition method. The simulation results of the optimal allocation of power flow provide comparable results with previous studies. This method produces a fair allocation of optimal transmission loss costs for both integrated and bilateral parties. The proportion allocation of the transmission lines loss incurred by the integrated system and bilateral contracts reflects a fair allocation of R. 852.589 and R. 805.193, respectively.

2018

The recent widespread restructuring and unbundling of the electricity industry has introduced some changes in the organization of the sector, thereby creating a more competitive environment in which each participant must bear its own cost and be responsible for its own contribution to losses in the system. The allocation of transmission losses has become an important issue as this determines how and what to charge each of the participants in the industry. This allocation is best assessed and based on their individual contributions to grid losses. Earlier methods used in loss allocation include: The Pro rata approach which arbitrarily allocates 50% each to the load and generator; the Marginal procedure allocation, which is either positive or negative; the Proportional sharing method which bases its allocation on the Kirchhoff's current law and allocates no losses to the transmission line and the Equilateral bilateral exchange (EBE) method. Most of the other methods, such as the Game theory method, Circuit theory method, Graph theory method, and Optimization methods are either mathematically complex in operation or time-consuming. And till date, none of these methods could be used to allocate transmission losses with fairness and transparency. Currently, power loss measurements have been estimated based on ideal conditions in which there exist a balanced load and reactive power, while the inefficiency caused by distortion and the unbalanced load is not usually taken into consideration. This research introduces a novel and a fairer method of determining power losses by using the Thévenin impedance in calculating the line parameters used in the determination of power losses. Since losses associated with a transmission power line depend on the wire resistance and the line current (I 2 R), the Thévenin equivalent of the system is calculated from the point of connecting each participant (generator or load), i.e. the point of common coupling, to determine the system losses without prior knowledge of the power system supply quantities. This thesis identifies the avoidable losses in the system, which participants pay for because of the inadequacy of current methods which use only reactive powers (inductive and capacitive) to determine the power losses in the allocation of losses and in the calculation of the power system tariff. This report elucidates how to estimate the 3.

IEEE Transactions on Power Systems, 1997

This paper presents derivations of basic formulae for computing the contributions of each economic transaction to the network power flows throughout the system in steady-state operation of interconnected electric power systems. It is shown that the net system power imbalance caused by each transaction can be obtained as a function of all transactions present on the system. In addition, formulae are proposed for calculating the contributions of every ancillary generation unit to each transaction. This generation is needed to balance the system in response to economic transactions. Formulae supporting this are based on reformulating the load flow problem in terms of distributed slack bus.

The problem of Transmission Loss Allocation (TLA) among the power system agents has become more important with the increase of the competition level in electricity markets. In this paper different Transmission Loss Allocation methodologies are considered. The comparison between them, which is not available in the literature, has been made. The methods considered in this paper are; Postage Stamp (PS), Proportional Sharing Principle (PSP) and Loss Function Decomposition (LFD) methods. Algorithms have been implemented for these methods. These methodologies are illustrated on IEEE 5-bus system and IEEE-14 bus system. The theoretical values are verified with the simulation results obtained from the MATLAB programming.

IEEE Transactions on Power Systems, 2000

2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262), 2001

This paper proposes a framework of transaction based power flow analysis (TBPF) for transmission utilization allocation. The TBPF utilizes distributed purchase-sale pairs to replace the role of a single slack bus on energy imbalance during power flow calculation iterations. To compare with conventional power flow analysis, accurate allocation of use-of-transmission is part of a TBPF solution. In particular, the TBPF is able to identify interaction components among transactions as well as the effect of reactive power on transmission losses and active power flows. T wo allocation rules for cross terms are proposed to hedge firm or existing transactions against market risk. The standard WSCC 9 bus system is used to demonstrate the performance of the TBPF.

International Journal of Global Energy Issues, 2007

This paper discusses an integrated framework for cost allocation of energy losses of electric distribution systems under liberalised energy markets.