Transmission cost allocation based on the modified Z-bus

International Journal of Electrical Power & Energy Systems, 2014

This paper presents a new method to allocate the transmission cost among generators and loads. The allocation is calculated for each transmission line through the identification and quantification of a fair distribution of both generators and loads. This method is based on circuit theory using modified impedance matrix. A two-step scheme is performed here: (1) in order to determine the participation of generators in the costs of the transmission network the generators are modeled as current sources and loads as constant impedances. (2) to determine the contributions of loads in the cost of the transmission network the loads are modeled as current sources and generators as constant impedances. Numerical results with a four-bus test system, as well as with IEEE 24-bus test system are reported and discussed to demonstrate the applicability of the proposed method.

Energy Conversion and Management, 2011

The transmission loss allocation problem in a deregulated electric power system is first discussed in this paper and then a new method is presented that is applicable under the pool market structure. Given the load flow solution of a network, the method can be implemented easily to allocate active power loss among the market participants. In this approach, a relationship between the bus current injections and the generator or load currents is first determined using a power invariant matrix and then Z-bus matrix is modified, which allows the real power loss of the network to be expressed in terms of generator or load currents. The modified Z-bus method provides the opportunity to allocate total losses to both generators and loads separately. This is while common Z-bus method is only capable of allocating losses to equivalent injected current at each bus. An example, with a six-bus test system is used to illustrate the main steps of the proposed allocation strategy, and numerical results obtained with the IEEE 14-bus system are used to assess the quality of loss allocation procedure.

IEEE Transactions on Power Systems, 2007

This paper addresses the problem of allocating the cost of the transmission network to generators and demands. A physically-based network usage procedure is proposed. This procedure exhibits desirable apportioning properties and is easy to implement and understand. A case study based on the IEEE 24-bus system is used to illustrate the working of the proposed technique. Some relevant conclusions are finally drawn.

This paper proposes a systematic method to allocate the power flow and loss for deregulated transmission systems. The proposed method is developed based on the basic circuit theories, equivalent current injection and equivalent impedance. Four steps are used to trace the voltages, currents, power flows, and losses contributed by each generator sequentially. Using this method, the real and reactive power on each transmission lines and their sources and destinations can be calculated. The loss allocation of each line, which is produced by each generator, can also be obtained. Test results show that the proposed method can satisfy the power flow equation, the power balance equation and the basic circuit theories. Comparisons with previous methods are also provided to demonstrate the contributions of the proposed method.

2007

This paper addresses the problem of allocating the cost of the transmission network to generators and demands. A physically-based network usage procedure is proposed. This procedure exhibits desirable apportioning properties and is easy to implement and understand. A case study based on the IEEE 24-bus system is used to illustrate the working of the proposed technique. Some relevant conclusions are finally drawn.

In this paper, a new method is proposed to allocate transmission loss in pool-based electricity markets. This method is based on using the impedance matrix of the network and the admittance equivalent circuit seen from the network buses. After performing load flow equations, the losses of each bus are calculated using the impedance matrix of the network and the reduced admittance matrix and the injected currents from each bus. These losses are properly and fairly shared between network buses for fair loss allocation in proportion to the percent of penetration the currents of each bus. Furthermore, using partial derivatives of the active power losses with respect to the bus currents' coefficients, a sensitivity analysis has been done for proving the fairness of the proposed method. In addition to its simplicity, the suggested method assigns the losses properly and fairly between the buses. Finally, this method has been tested on a benchmark IEEE 14-bus network, and the results ar...

International Journal of Electrical Power & Energy Systems, 2012

In the deregulated power system, it is necessary to develop an appropriate pricing scheme that can provide the useful economic information to market users, such as generation companies, transmission companies and customers. However, accurately assessment and allocating the transmission cost in the transmission pricing scheme is a challenge, although many methods have been proposed. The objective of this paper is to propose a simple transmission pricing scheme using tracing method based on the proportional tree, in which transmission fixed cost, congestion cost and loss cost are considered. A case study based on IEEE 24-bus test system is applied to assess the effectiveness of the cost allocation procedure.

This paper suggests an improved method for usage allocation to individual generators in a deregulated power system. Based on solved load flow, the method converts power injections and line flows into real and imaginary current injections and flows. These currents are then represented independently as real and imaginary current networks. Since current networks are acyclic lossless networks, proportional sharing principle and graph theory is used to trace the relationship between current sources and current sinks. The contributions from each current source are finally translated into power contributions to each load, line flows and losses. IEEE 14-bus test system is used to illustrate the effectiveness of the method. Comparison of the results with previous methods is also given

In a competitive electricity market, the transmission costs should be fairly distributed amongst the users of the transmission facilities, in order to attain optimal usage of the transmission facilities and to provide correct economic signal for future generation planning and load placement. In this paper, transmission costs are divided into three components; i.e. actual transmission usage cost, unused capacity cost, and network reliability cost; and is distributed amongst the users in a nondiscriminatory manner. The proposed algorithm has been implemented on a 9-bus test system and the results are compared with corresponding MW-Mile based method results.