Transmission Loss Allocation Research Articles

Review of Various Transmission Loss Allocation Methods: A Case Study of Integrated Nepal Power System using Best Method

This paper presents a review of the most relevant and practical methods for allocating transmission loss in a deregulated market. They are the pro-rata (PR) method, the marginal allocation (ITL) method, the proportional sharing (PS) method, and the Z-Bus method. This study has also performed a qualitative comparison of four methods using the IEEE 14 bus system. Finally, the Z-Bus method is selected as the best option for implementation in the Integrated Nepalese Power System Network (INPS). As of 2022, the loss allocation is determined at all 132 and 220 kV substations of INPS. The study of transmission loss allocation for INPS is carried out for six different cases, considering the variation in patterns of energy generation and demand, i.e., system full generation, summer peak, winter peak, average peak, dry peak, and contingency condition. The result shows the load, like Kathmandu Valley, which is in the region of generation, and the generator, like in the eastern region, which is in the region of demand, are mostly compensated with negative losses. Loads in the western region and generators like the Upper Tamakhoshi, which are far from the generator or load, are assigned the highest positive loss. Loss allocation to load and generator can vary depending on the loading conditions that INPS is operating under. The generation is comparably distributed in the full generation, summer, and contingency instances; as a result, the loss allocation to both loads and generators is significant. However, the bulk of losses are only attributed to the generator side in the three other scenarios with less generation, when the majority of the generation is only aggregated in a specific location. This is a result of the remote generator's long-distance power flow, which raises system loss. As a result, the Z-Bus method assigned the generator side the majority of the losses. Additionally, the majority of INPS's generation is determined to be remotely located, which increases their risk of transmission loss. Because of this, INPS is best served by the Z-Bus approach, which takes into account the locations of buses within the network. In order to minimize system loss, this encourages big demand or generation to be positioned close to the center of generation or demand.

Energy Bidding Quadratic Model and the Use of the B-Loss Matrix for Determining Consumer Energy Price

The liberalization trend has led to electric restructuring in market industries. At the start of the 1990s, it was recommended to shift the electricity business from a monopoly to a competitive system. The electric power problem becomes more complex from competition because competitors must be ready to win or lose. The method that has succeeded in determining energy prices in competition is the locational marginal price method implemented by the New York Service Operator. In general, the characteristic of the supplier offers are in step function forms, so optimizing prices and allocating transmission losses are a problem. This paper proposes a method for determining electrical energy prices on the consumer side in each location. The method uses a quadratic approach to perform direct method optimization. The transmission losses are calculated through the B-loss matrix approach, and then allocations of the transmission losses are separated with the proportional method. Simulation results for three locations with six suppliers, as well as on a larger scale (118 buses, 54 generators) were obtained.

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

Transmission Loss Allocation in Deregulated Power Systems Comprising Renewable Distributed Generation

Transmission Loss Allocation in Deregulated Power Systems Comprising Renewable Distributed Generation

Optimal cost allocation algorithm of transmission losses to bilateral contracts

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.

Enhancement of electricity wheeling charges by incorporating FACTS controller in restructured power system

In the past few decades, the demand for electricity has increased substantially. A number of factors affect this rapid rise in electricity demand. With this increased demand the role of transmission network becomes crucial for suitable operation, especially under restructured environment. The different limitations such as stability limit, voltage limit and thermal limits enforce restrictions on power wheeling capability of transmission lines. The major issues associated with power industry especially in the pool-based market are the recovery of transmission costs apportioned between the diverse. Restructuring of the electricity supply industry has taken place around the world. This restructuring consists of various new aspects such as transmission embedded cost allocation, reactive power cost allocation, transmission loss allocation, the impact of power flow regulating devices etc. Many methodologies and algorithms were proposed for addressing these issues. In this paper, FACTS incorporated power flow model is used for the determination of flow of real and reactive power by using the power flow tracing principle, which involves matrix properties for the real and reactive power allocation and cost allocation for different participants. FACTS devices which have the capability of regulating the power flow and voltage support at the buses. Hence UPFC incorporated in the transmission system have been considered in this paper. Comparative results with and without FACT controller are present for the sample 5 bus system and methodology also tested on IEEE 14 bus system.

Network loss management and allocating the transmission losses to loads and generation units according to their transactions

During recent years, allocating the network losses to loads and generation units based on network transactions is an important issue in the power industry. This study presents an appropriate method to allocate the network losses to loads and generation units according to their network transactions. This method is appropriate and faster than other loss allocation techniques and does not consider unreasonable assumptions in the loss allocation process. This method explicitly assigns the network losses according to individual transactions, and this leads to allocate the network losses among all network transactions. This approach is based on the share of the loads and generation units on active and reactive power flows passing through the lines according to transactions. The implementation of the method on large networks is simple and fast. To approve the performance of the presented method, the proposed loss allocation technique has been applied to a three-bus case study system and the IEEE 14-bus test system. Also, several different transaction modes are used to show the performance of the presented method for transmission loss allocation based on transactions.

Fairness in Allocation of Transmission Losses to Bilateral Contracts with Superposition and Decomposition Techniques

Market mechanism allows the involvement of bilateral contracts in the electricity business competition. However, the participation of bilateral contracts will face various problems, especially the fair allocation of transmission losses. This paper presents the reasonableness share allocation of transmission line losses based on the separation method of current flow in each transmission line from the converging power flow. The methodology is to combine superposition and decomposition techniques in order to produce accurate transmission loss allocation for bilateral parties. The superposition technique formulates the current flow separation in each transmission line, and the decomposition technique defines the allocation of power losses in each transmission line. This technique is called the Combination of the Superposition and Decomposition Method (CSDM). A numerical test has been performed for method validation and compared with the τ-value method. This method has been able to provide a solution for the allocation of reasonable transmission losses. Based on the CSDM, the portion of transmission loss allocation for bilateral contracts compared with the integrated system is 47.9% and 52.1%, respectively. At the same time, the τ-value method provided the proportion of the bilateral contracts compared with the respective integrated system is 80.5% and 19.5%.

A New Technique for Transmission Loss Allocation in a Deregulated Electricity Market

In a present day a necessity for fair allocation of transmission loss in a deregulated electricity market. This paper presents modifiedZbus loss allocation method to calculate the allocation of transmission loss loss . The procedure depends on straightforward circuit laws and doesn't include any suppositions. results obtained for IEEE 14 Bus system are analysed with the other present methods.

An investigation on apportion of mathematical loss in transmission loss/cost allocation approach

<p>Cost allocation of highly non-linear transmission loss is complex and essential in competitive electricity market. In most of the existing transmission loss/cost allocation approaches, real power loss depends on selection of slack bus and hence the cost of transmission losses which are allocated to the generators and the loads also varies. In this paper, a complete analysis on the impact of slack bus selection on transmission loss allocation with and without mathematical loss is made. One of the existing approaches, proportional generation and proportional load (PGPL) method is taken to illustrate the impact. Mathematical loss is the loss without generation and load in the network and can be obtained from power flow solution by taking generation and load as zero. The cost incurred for this mathematical loss is allocated to the transmission lines while the cost of transmission loss due to bilateral contracts is allocated among the sources and the consumers. These loss/cost allocations with and without considering mathematical loss is shown using an IEEE 30 bus, 57 bus, 75 bus and 118 bus systems. The simulation results are obtained using MATLAB R2014a.<em></em></p>

A Novel Technique for Transmission Loss Allocation in Restructured Power System

Transmission loss allocation in a restructured power system is vital in today’s electricity market around the world. The problem of transmission loss allocation among the various participants is getting more attention with the increase of the competition level in electricity markets. In this paper, a novel routing algorithm with minimum transmission loss is proposed for judicious allocation of transmission losses over a network. Proposed routing algorithm computes the power flow path through transmission line from the individual generator to load utilizing the shortest path with minimum loss criterion. The load demand is fulfilled with the power flow through the decisively selected transmission path. The new method of transmission loss allocation has distinct advantages over existing methods as locational dependence of loss allocation to both generator and load. The proposed algorithm is implemented on IEEE-30 bus system. The experimental results are obtained with proposed routing algorithm and compared with existing method. Results obtained using proposed method illustrate significant improvements in reducing the transmission losses.

Modified penalized quoted cost method for transmission loss allocation including reactive power demand in deregulated electricity market

Abstract Transmission loss/cost allocation to the individual buses in a fair way is an essential issue in restructured electricity market. This paper splits active power transmission loss into two components namely real and reactive loss component. The real and reactive loss components are due to the real power transaction from the generator to the load and reactive power demand of the load respectively. The active power loss changes due to the reactive power loads and this increase in loss are allocated to the relevant loads based on load sensitivity factor (LSF). The loss allocation using LSF is a valid approach as it is derived from solved load flow solution. The cost allocation of real loss component to a transaction and reactive loss component to loads is based on the loss contribution fraction (LCF) and LSF respectively. The highlight of this paper is to allocate real loss component to the respective buses equally and to allocate the cost of reactive loss component to the respective loads in a fair way. This paper also presents a detailed discussion on impact of mathematical loss and comparison with four existing loss allocation methods. All the methods are discussed by considering with and without reactive power load. The effectiveness of the proposed approach is illustrated using a sample four bus and 30 bus IEEE system.

Comparison of Transmission Loss Allocation by Proportional Sharing Principle Method and Aumann Shapley Method

In the current scenario of the electricity market in the world the cost allocation became the thematic part and the essential usage to individual distributor and to the consumer. Allocation is nothing but a share of anything that been shared in the equal amount to the assigned terms of the quantity. Here in the power sector, losses and the respective costs have been shared among the generators and the loads. To achieve the linear nature and invariant characteristics, allocation of losses is done. To such allocation of losses there are many methods, popular methods of them named, Proportional Sharing Principle Method and Aumann-Shapley Method are compared in this paper based on loss and cost allocation, and results are verified through Mat lab platform.

Allocation of transmission active losses through a novel power tracing‐based technique

One of the challenging issues in a restructured power system is fair allocation of transmission losses to its users. This study proposes two new algorithms to trace the active power produced (consumed) by the generators (loads) for assigning active losses to the generators or loads separately. In the proposed methods, there is no need to convert the study system to a system for which the active power at both ends of each transmission line are the same. In these algorithms, based on AC power flow calculations, new matrices called outflow-line and inflow-line are first created. Then, according to the properties of these matrices, four other matrices, which express active power flows of the transmission lines in terms of active power productions (consumptions) of the generators (loads), are then derived. These matrices are employed not only to allocate the active loss of every transmission line to each generator or load, but also to determine the contribution of each generator to the active power consumption of each load. The results obtained by implementing the proposed algorithms on a five-bus system and two IEEE standard systems indicate its superiority over some earlier methods.

Transmission loss allocation in bilateral or multilateral transaction-based markets

In this paper, the problem of transmission loss allocation has been studied and a new method for loss allocation in transaction-based markets has been proposed. To further this end, first transmission line loss equations were used with respect to bus injected currents. The share of each bus from the mentioned transmission line losses was determined. Then, this method was applied to the total network transmission lines. While considering the available transactions, the share of each bus from the total losses was acquired. The proposed method is based on the main network relations and no simplifying assumption has been used. Finally, the proposed method is based on a typical network.

Non-Linear Least Squares and Maximum Likelihood Estimation of Probability Density Function of Cross-Border Transmission Losses

In the modern power system, transmission losses play an increasingly important role in determining the costs of transmission system operators, in particular in cross-border energy exchange. A variety of transmission losses calculation methods are present in scientific literature in recent years, but regularly neglecting the measurement uncertainty, which is an important contribution in calculating the final cost of exchanged energy. Due to the significant cost of transmission losses in total costs, all transmission system operators are interested in discovering the probabilistic nature of transmission losses as a fundamental requirement for finding the fair method for transmission losses allocation. In this paper, transmission losses are simulated on 110-kV cross-border transmission line using an adaptive Monte Carlo method. The probability density estimation procedure is performed by the non-linear least-squares method, using the Levenberg–Marquardt algorithm. The Gaussian, log-normal, Rayleigh, four-parameter beta, generalized trapezoidal, and the sum of uniform and normal distribution are fitted and the quality of the distribution estimates is compared according to the corresponding values of the Kolmogorov–Smirnov statistic. Furthermore, an additional example presents a distribution fitting procedure on the zero-impedance data of the same transmission line.

Approach for allocation of transmission loss based on contribution of generators and loads in injected complex power into network lines

During recent years, the shift from monopoly integrated power systems to restructured power systems caused an increased competition among the electricity market. In restructured power systems, providing a fair and impartially service pricing is still in discussion on ‘who should be reprimand’ for the losses contribution. The loss allocation (LA) causes appropriate economic penalties or rewards to generators and consumers. This study presents a reasonable method for LA in power systems. This method is based on the injected active and reactive power into network lines. At first, the contribution of the loads in the loss of each line is obtained regardless of the generators. Then, the loss of lines is allocated to source buses and the contribution of each generator in the loss of each line is calculated. At the final step, a normalisation factor is introduced and the final contribution of each load and each generator in the loss of each line is calculated separately. The proposed algorithm is simple and easy to implement on the large-scale power systems.‏ This proposed method has been applied to the IEEE 14-bus and IEEE 30-bus test systems, and the obtained results are compared with other existing LA methods.

A New Methodology for Active Power Transmission Loss Allocation in Deregulated Power System

This paper presents a new method for transmission loss allocation in a deregulated power system. As the power loss is a nonlinear quantity, so to allocate the loss in a common transmission corrider is a difficult task. It allocates transmission losses to loads based on the actual power flow in the lossy lines due to the concerned load. Each lossy line is subdivided into as many sub-lines as corresponding to the numbers of load attached to it. The tracing of power flow through each sub-line is worked out by using proportional sharing method. The power loss in each lossy line is equal with the total loss due to all the sub-lines under it. Then by using Pro-rata for each lossy line, the individual loss for each sub-line is formulated. As the application of Pro-rata is limited to an individual line of the system, so the error in calculation is minimized. The total loss allocated to a particular load is the sum of losses occurred in each lossy lines through which the power is flowing to the concerned load. As this method is based on the actual flow of power in the transmission line corresponding to the concerned load, hence, the loss allocation made by the method gives proper and justifiable allocations to the different loads which are attached to the system.<strong> </strong>The proposed method is applied to a six-bus system and finds the mismatch in the commonly used methods. Then, it is applied to higher bus systems in which more accurate results are obtained compared to the other methods.

Cross‐border transmission line losses calculation using adaptive Monte–Carlo method

This study deals with calculation of transmission line losses. Having in mind that this type of losses, besides the line load and the other external input quantities such as atmospheric conditions, strongly depends on measurement uncertainty as well, the issue can be considered through finding the most convenient approach in calculation of measurement uncertainty. In this respect, two approaches (methods) are the most common: traditional method based on the guide to the expression of uncertainty in measurement (GUM) and the adaptive Monte–Carlo method (AMC). The study reveals the main disadvantages of the GUM, which is so far considered as a most accurate method. The observed drawbacks of the GUM can be successfully overcome by using of the AMC method. The comparison between the methods is performed on 110 kV cross-border transmission line from Croatian Transmission System Operator Ltd. The results show the great difference in the estimated variances, i.e. GUM variances are significantly overestimated what results in incorrect transmission losses allocation procedure with respect to its final financial effect. The study confirms that the AMC method is likely to be more practically suitable method for transmission line resistance and losses calculation.

Near‐real‐time loss allocation methodology based on the power system states

Power losses in transmission systems are most of the time seen as a small amount (2-5%) from the total power carried over the network. However, transmission loss allocation may play a crucial role in the congestion management of balancing markets. Several loss allocation and loss cost allocation methods have been proposed and implemented in different markets. Most of these methods are intended to be used post-market. This study presents a novel near-real-time loss allocation method suitable to be applied in real-time markets as envisioned in the smart grid context. The proposed method allocates the total system losses fairly to all the demand and generator buses, by taking into account the dynamical changes of the power network states, which are provided by an accurate state estimation. The power flows required to determine the allocated losses are executed after an economic dispatch procedure that ignores losses, making the choice of the slack bus an independent factor. The proposed method can be used as an accurate real-time pricing for network usage while the resolving of transmission congestion can be more reliable.