Transmission Network Cost Research Articles

Optimal planning of a micro‐grid containing tidal barrage equipped to the hydro‐pumps

AbstractDue to the advantages of micro‐grids including power losses and voltage drops reduction, reliability improvement and reduction in transmission network cost, numerous clean micro‐grids including renewable resources such as wind, tidal and solar are developed in different countries of world. The investment cost of the renewable energy‐based generation units especially tidal barrages is high, and to generate the cost‐effective electricity from the renewable resources, the optimization process should be performed. In this paper, optimal planning of a micro‐grid containing energy storage device and new mixture of renewable resources including tidal barrage and photovoltaic system is performed. For this purpose, optimal characteristics of barrage type tidal plant including number of turbines, sluices and hydro‐pumps, turbine tip and hub diameters and sluice width are determined to maximum energy of tidal plant is generated. Then, number of photovoltaic systems and batteries are obtained to supply the required load in minimum cost. To optimize the objective functions, different heuristic approaches including particle swarm, genetic and imperial competitive algorithms (ICAs) are applied, in the paper. To study the effectiveness of the proposed approach, optimal planning of a micro‐grid is performed. It is deduced from the numerical results that the particle swarm method has performed best in determining the optimal solution.

Transmission network tariff volatility assessment under UPFC‐integrated system and N‐1 contingency condition

AbstractIn the restructured electricity markets, transmission usage, usage costs, and loss allocation are critical issues for recovering network embedded and maintenance costs from network users. However, because of the integration of the flexible alternating current transmission system (FACTS) and the occurrence of power system contingencies, this allocation is more complex and critical from the utility's perspective, as it may cause volatility in transmission network costs. In this work, the unified power flow controller (UPFC) is utilized to show the effect of its integration on the system cost and cost allocation. Further, contingency conditions are common in power systems. Therefore, for determining usage, usage cost, and loss allocation volatility under UPFC‐integrated system and N‐1 contingency conditions, this work utilized a power flow tracing‐based transmission usage allocation technique. Reliability factors are used to determine transmission line flows in the event of a failure. Furthermore, contingency line flows are employed to assess transmission tariff volatility in terms of risk premiums. The cost of transmission utilization is recovered using a modified MW‐mile technique. The devised approach was put to the test on a 6‐bus system and an IEEE 14‐bus system.

Recent Development in the Design of Wind Deflectors for Vertical Axis Wind Turbine: A Review

Developments in the design of wind turbines with augmentation are advancing around the globe with the goal of generating electricity close to the user in built-up areas. This is certain to help lessen the power generation load as well as distribution and transmission network costs by reducing the distance between the user and the power source. The main objectives driving the development and advancement of vertical-axis wind turbines are increasing the power coefficient and the torque coefficient by optimizing the upstream wind striking on the rotor blades. Unlike horizontal-axis wind turbines, vertical axis turbines generate not only positive torque but also negative torque during operation. The negative torque generated by the returning blade is a key issue for vertical-axis wind turbines (VAWTs) that is counterproductive. Installation of wind deflectors for flow augmentation helps to reduce the negative torque generated by the returning blades as well as enhance the positive torque by creating a diversion in the upstream wind towards the forwarding blade during operation. This paper reviews various designs, experiments, and CFD simulations of wind deflectors reported to date. Optimization techniques for VAWTs incorporating wind deflectors are discussed in detail. The main focus of the review was on the installation position and orientation of the deflectors and their potential contribution to increasing the power coefficient. Topics for future study are suggested in the conclusion section of the paper.

Transmission Network Cost Allocation Based on Superposition Theorem (Dept.E)

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Allocation of transmission network cost using modified [formula omitted] matrix

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.

Pricing strategy of transmission network wheeling cost considering short-term operational cost

A pricing model based on the long-term incremental cost method is proposed for calculating the wheeling cost of transmission network, which considers the influence of short-term operational cost on the investment time of transmission network components and the wheeling cost of transmission network. To simplify the analysis, the short-term operational cost considered is mainly the congestion management cost. The proposed model is applied respectively to the dual-bus test system and IEEE 30-bus test system, and compared with the traditional pricing model, which verifies its effectiveness.

Transmission Network Cost Allocation Considering Counterflows

This paper presents a methodology for allocation of fixed costs of transmission based on the electric circuit theory. The use of the transmission network is determined from the contribution of each generator and load to the power flow in lines. The allocation process is carried out considering counterflows and distinguishing between the usage and reserve margin of lines. According to the results, the methodology proved to be adequate, since it ensures complete recovery of transmission costs and provides financial incentives to agents who contribute to the security and reliability of the system and to the postponement of investment in transmission as well.

Transmission network cost allocation with nodal pricing approach based on Ramsey pricing concept

This study presents a new method to allocate electricity transmission costs from nodal pricing viewpoint based on Ramsey pricing concept. Nodal pricing method is the most popular method of transmission pricing, which is based on the difference between marginal cost prices at nodes in transmission systems. The main drawback of this method is that it is not able to produce enough revenue to recover the total transmission network costs. To solve this problem, the marginal prices can be adjusted in such a way that nodal pricing can recover the total transmission costs. From economists' point of view, if the marginal cost prices (first-best prices) do not satisfy other economic criteria, the second-best prices can be achieved by maximising the social welfare subject to budget constraint. The latter pricing approach is called Ramsey pricing which is varied in proportion to the inverse of demand elasticity. A new transmission cost allocation method based on the nodal pricing approach is proposed, in which the marginal prices are controlled by Ramsey pricing concept based on the inverse proportionality of price elasticity. The proposed method is implemented on IEEE 24 bus test system and the obtained results are reported. To show its validity and superiority, the necessary comparison is made with one of the relevant references.

An optimization planning technique for Suez Canal Network in Egypt

This paper introduces a proposed optimization technique POT for predicting the peak load demand and planning of transmission line systems. Many of traditional methods have been presented for long-term load forecasting of electrical power systems. But, the results of these methods are approximated. Therefore, the artificial neural network (ANN) technique for long-term peak load forecasting is modified and discussed as a modern technique in long-term load forecasting. The modified technique is applied on the Egyptian electrical network dependent on its historical data to predict the electrical peak load demand forecasting up to year 2017. This technique is compared with extrapolation of trend curves as a traditional method. The POT is applied also to obtain the optimal planning of transmission lines for the 220 kV of Suez Canal Network (SCN) using the ANN technique. The minimization of the transmission network costs are considered as an objective function, while the transmission lines (TL) planning constraints are satisfied. Zafarana site on the Red Sea coast is considered as an optimal site for installing big wind farm (WF) units in Egypt. So, the POT is applied to plan both the peak load and the electrical transmission of SCN with and without considering WF to develop the impact of WF units on the electrical transmission system of Egypt, considering the reliability constraints which were taken as a separate model in the previous techniques. The application on SCN shows the capability and the efficiently of the proposed techniques to obtain the predicting peak load demand and the optimal planning of transmission lines of SCN up to year 2017.

Transmission cost allocation based on use of reliability margin under contingency conditions

A reliability-based method for allocating the cost of transmission networks is presented. The cost of a transmission line is divided into two components. The first component corresponds to a part of the line capacity, which is used under normal conditions. The second component corresponds to a portion of the line capacity, which is only used under contingency conditions. The latter is the part that market agents use to calculate the reliability benefit charges of the line. In the proposed method, a probabilistic index is defined based on single-contingency analysis, which measures the reliability margin of each line for each transaction. Furthermore, the cost components associated with capacity use and reliability benefit charges are determined based on the actual reliability margin of lines. This method can be used to provide an equitable means for allocating the cost of transmission network among users of a bilateral market model. The proposed method is illustrated in a small power system as well as the 24-bus IEEE-RTS, and its conceptual and computational feasibility are demonstrated.

Electricity transmission network optimization model of supply and demand – the case in Taiwan electricity transmission system

The electricity system can be divided into power generation, transmission and distribution subsystems from the structure point of view. Electricity business is positioned as a public business and regulated by pricing and quantities due to the high publicly utilization. The power transmission system is responsible for power transmission from power generation plants to the areas of power utilization. Since there is the characteristic that electricity needs to produce and sell with immediate and instant balance, it is required to construct the complete power transmission network in charge of the power dispatching in order to provide stable electricity. The price of purchases and sales is closely related with the necessity of power supply and demand. The purpose of this paper is to introduce the optimization model of power supply and demand in the independent power transmission network for the maximization of consumer and producer's surplus in the liberalization of electricity business.We apply this model to discussing the relationships of electricity quantity and price of purchases and sales. In addition, the sensitive analysis is introduced as well. We conclude that the maximal profit of power transmission network will be decreased when quantity of power utilization, cost of power generation and maintenance cost of transmission network are increasing. Instead, the maximal profit of power transmission network will be increased when power transmission rate is increasing.

Nodal Price Control: A Mechanism for Transmission Network Cost Allocation

This paper presents an approach for the allocation of transmission network costs by controlling the nodal electricity prices. The proposed approach introduces generation and nodal injection penalties into the traditional economic dispatch so as to create nodal price differences that recover the required transmission revenue from the resulting congestion rent. As a consequence, the new electricity prices reflect not only the marginal costs of production subject to transmission constraints but also the capital costs of the network. This is the approach commonly adopted with most commodities whose price includes the unit cost of the good itself as well as the transportation cost from the production centers to the final consumer.

Transmission network cost allocation based on equivalent bilateral exchanges

This paper presents a novel methodology for allocating the cost of a transmission network to its users based on the principle of equivalent bilateral exchanges, which states that after all physical laws governing the flow of power have been met, each demand is assigned a fraction of each generation and each generator is assigned a fraction of each demand in a uniform manner. Transmission cost allocation based on this principle presents several advantages, namely, independence from the choice of the slack bus, recognition of counter-flows, and transmission use charges that are stable and always positive.

On the Selection of the Slack Bus in Mechanisms for Transmission Network Cost Allocation that are Based on Network Utilization

On the Selection of the Slack Bus in Mechanisms for Transmission Network Cost Allocation that are Based on Network Utilization