Open Access Transmission Research Articles

An optimal transport theory based approach for efficient dispatch of transactions in energy markets

AbstractNowadays, transactive energy markets (TEMs) are emerging as interesting frameworks in deregulated power markets to control the balance of supply and demand in the entire electrical network. Due to wide deployment of renewable energy resources, grid connected micro‐grids, and open access transmission and distribution networks, the planning and operation of TEMs become complex. So, an efficient optimal dispatch model for TEMs should be developed to achieve the objectives of TEMs, such as feasible sizes of transactions and optimal dispatch of these transactions with minimal operating costs. The transactive dispatch problem is similar to the resource allocation/matching problem. Recently, optimal transport (OT) has received significant attention in various fields including optimization theory and resource matching problems due to its potency and relevance in modeling and optimization. An OT‐based approach is proposed here for optimal dispatch of transactions in energy markets while minimizing the cost of transactions considering the operating constraints of the system. The proposed approach can efficiently determine the feasible sizes of transactions without any security issues. The optimal solutions of the OT‐based approach are obtained using a Sinkhorn iterative technique. Also, the load uncertainties are considered in this work to analyse the impacts of load uncertainties on the optimal dispatch of transactions. The numerical simulation results on the modified IEEE 9‐bus system, modified IEEE 57‐bus system, modified IEEE 118‐bus system, and Indian Northern Regional Power Grid (NRPG) system illustrate the efficacy of the proposed OT‐based framework.

A Comprehensive Review of Congestion Management in Power System

In recent decades, restructuring has cut across all probable domains, involving the power supply industry. The restructuring has brought about considerable changes whereby electricity is now a commodity and has become a deregulated one. These competitive markets have paved the way for countless entrants. This has caused overload and congestion on transmission lines. In addition, the open access transmission network has created a more intensified congestion issue. Therefore, congestion management on power systems is relevant and central significance to the power industry. This manuscript reviews few congestion management techniques, consists of Reprogramming Generation (GR), Load Shedding, Optimal Distributed Generation (DG) Location, Nodal Pricing, Free Methods, Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Fuzzy Logic System Method, as well as Additional Renewable Energy Sources. In this manuscript a review work is performed to unite the entire publications on congestion management.

Dynamic economic dispatch of transactive energy market using dynamic programming with state-restructuring feature

Nowadays, transactive energy markets (TEMs) are emerging as interesting frameworks in deregulated power markets (DPMs) to control the balance of supply and demand in the entire electrical infrastructure. TEMs can facilitate power delivery with high efficiency and more economic benefits without any security issues and also encourage interaction between market participants in the DPMs. Due to wide deployment of renewable energy resources, open access transmission systems, and improper dispatch of transactions, the operation of TEMs becomes complex. So, an appropriate dispatch model for TEMs should be designed to achieve the TEMs objectives. This paper presents a novel dynamic programming (DP) based dispatch model for optimal dispatch of transactions without any security and economic issues. New techniques, i.e., variable step size (VSS) and state-restructuring (SR) features are proposed to combine with DP for solving the proposed dynamic dispatch problem of TEMs with minimization of the operational cost of transactions. The VSS and SR features are integrated with DP to reduce the computational burden and operational complexity of the proposed problem remarkably. Also, the proposed approach determines the power contribution of generation units to transactions in order to accurately assess the cost of transactions. An index, relative load-contribution factor is proposed in this paper to analyse the behaviour of generation units with respect to load variations of the transactions. Numerical simulation results on the modified IEEE 14-bus system and modified IEEE 118-bus system illustrate the efficacy of the proposed DP based model in solving the proposed dispatch problem of TEMs with optimal operational costs of the system. The results highlight the proposed approach benefits and provide a strong validation of its applicability to large-scale TEMs.

Optimal Dispatch of Renewable and Virtual Power Plants in Smart Grid Environment through Bilateral Transactions

In a competitive power market, assessment of optimal bilateral transactions is very important for achieving more financial benefits without any stability, security and reliability issues. Due to the open access transmission network and the wide deployment of renewable energy sources (RES) and virtual power plants (VPP), dispatch of VPP and RES units through bilateral transactions become complex. This paper presents an efficient approach for the determination of optimal and feasible bilateral transactions among the power traders in a smart grid based on proposed factors, i.e., active participation factor (APF), maximum loading point (MLP) and load distribution factor (LDF). The objective of the proposed tri-level dispatch model is to minimize the cost of generation and transmission cost of transactions by using a mixed integer nonlinear programming (MINLP) technique. The proposed market dispatch model efficiently gets rid of the congestion in the transmission network and enhances the power transfer capability of the network, i.e., transaction dispatch capability of the network. The performance of the proposed tri-level model has been validated on the modified IEEE-14 bus system and modified IEEE-30 bus system.

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.

Islanded microgrid congestion control by load prioritization and shedding using ABC algorithm

The continued growth in load demand and the gradual change of generation sources to smaller distributed plants utilizing renewable energy sources (RESs), which supply power intermittently, is likely to strain existing power systems and cause congestion. Congestion management still remains a challenging issue in open access transmission and distribution systems. Conventionally, this is achieved by load shedding and generator rescheduling. In this study, the control of the system congestion on an islanded micro grid (MG) supplied by RESs is analyzed using artificial bee colony (ABC) algorithm. Different buses are assigned priority indices which forms the basis of the determination of which loads and what amount of load to shed at any particular time during islanding mode operation. This is to ensure as minimal load as possible is shed during a contingency that leads to loss of mains and ensure a congestion free microgrid operation. This is tested and verified on a modified IEEE 30-bus distribution systems on MATLAB platform. The results are compared with other algorithms to prove the applicability of this approach.

Transmission Lines: Designing for Open Access Transmission [In My View

Discusses power system design for open access transmission. Hundreds of technical papers were written prior to deregulation in the 1990s regarding the optimization of new transmission line designs. A common goal was to minimize electrical losses and capital investment in conductors, structures, and rights of way by choosing the right conductor size within the boundaries of corona and electromagnetic fields. At the time, it was, to some extent, possible to predict the line power flow for new lines at least 10–20 years into the future. Since the advent of open-access transmission, the development of new power generation by wind and solar sources, the sometimes rapidly shifting fuel costs (i.e., gas versus nuclear and coal), and environmental restrictions on conventional generation, it is no longer possible to predict the line-load magnitude and daily load shape for most new lines over their expected design life of 40 years.

Distribution Factor Method Modified for Determine of Load Contribute based on the Power Factor in Transmission Line

<p>This paper proposes a modification of distribution factor methods for identifying the load contribute in a transmission open access, with regard to the load power factor. This method may be considered as the first pricing strategy to be proposed in bilateral transaction for transmission usage, based on the actual use of the transmission network. The merit of this method relies on the existence of a load power factor with GLDF methods, which allocate the transmission cost, not only based on the amount of power flow but also on the load characteristic. A case study utilizing the IEEE 30-bus system was conducted to illustrate the contribution of the proposed method in allocating the transmission usage to the user in a fair manner.</p>

Tariff calculating model for natural gas transportation through open access transmission pipeline with multi tariff system to increase gas usage as clean energy

The purpose of this study is to model the different tariffs on the transportation of natural gas through a pipeline for several shipper classes in an open access natural gas pipeline transmission line called a multi-tariff system. The determination of the natural gas tariff through the Open Access pipeline in Indonesia is mostly set using a distance system with the same value for all types of the shipper. The principle of justice is considered to be achieved from uniform tariffs for all the shipper, whereas in practice the separation of tariffs for each shipper group is currently essential. The proposed new tariff modeling is done by modifying the initial equations of the single-tariff model. Besides giving a new model proposal of tariff calculation for the multi-tariff system, in this research will also be modified free cash flow for new tariff calculation scheme and will be done the validity test on the formula. So that will get a multi-tariff calculation model which can become one of proposal material enter for Regulators to be able to set a fair tariff for the shipper without changing the economics of the transporter and can produce competitive gas prices to substitute clean energy sources for certain consumers such as electricity generation.

Congestion management in deregulated power system using hybrid cat-firefly algorithm with TCSC and SVC FACTS devices

Purpose The loading and power variations in the power system, especially for the peak hours have abundant concussion on the loading patterns of the open access transmission system. During such unconditional state of loading the transmission line parameters and the line voltages show a substandard profile, which depicts exaction of congestion management of the power line in such events. The purpose of this paper is to present an uncomplicated and economical model for congestion management using flexible AC transmission system (FACTS) devices. Design/methodology/approach The approach desires a two-step procedure, first by optimal placement of thyristor controlled series capacitor (TCSC) and static VAR compensator (SVC) as FACTS devices in the network; second tuning the control parameters to their optimized values. The optimal location and tuning of TCSC and SVC represents a hectic optimization problem, due to its multi-objective and constrained nature. Hence, a reassuring heuristic optimization algorithm inspired by behavior of cat and firefly is employed to find the optimal placement and tuning of TCSC and SVC. Findings The effectiveness of the proposed model is tested through simulation on standard IEEE 14-bus system. The proposed approach proves to be better than the earlier existing approaches in the literature. Research limitations/implications With the completed simulation and results, it is proved that the proposed scheme has reduced the congestion in line, thereby increasing the voltage stability along with improved loading capability for the congested lines. Practical implications The usefulness of the proposed scheme is justified with the computed results, giving convenience for implementation to any practical transmission network. Originality/value This paper fulfills an identified need to study exaction of congestion management of the power line.

Improving Regulatory Environment for a Regional Power Market in South Asia

South Asian countries continue to face challenges such as poor access to energy, energy shortages, and concerns for energy security. The availability of primary sources for generating electricity vary across the region, and the potential for operational synergy provide room for cross-border electricity trade cooperation in the region. The economic and environmental benefits of such cooperation can be harnessed to its full potential if the existing barriers to enhance power marketing and barriers to cross- border trade of electricity can be reduced. For trade of electricity to be smooth across the region, policy and regulatory environments governing the power sector need to be harmonized. The adoption of the South Asian Association for Regional Cooperation (SAARC) Framework Agreement for Energy Cooperation (Electricity) during the 5th SAARC Energy Ministers’ Meeting and the 18th SAARC declaration in Kathmandu in November 2014 is a step toward achieving this harmonization. This paper examines the power sector regulatory and policy environment in the South Asian countries in the context of cross-border power trade. It identifies key issues influencing rapid development of cross-border power trade and provides specific recommendations to address these. Among others, some of the key areas that need attention are providing trading licenses, allowing open access transmission and distribution networks, coordinating transmission planning and power system operation, forming a nodal agency for cross-border power trading, and resolving disputes. The paper provides recommendations to improve policy and regulatory environment in the short, medium, and long term. These include, among others, identifying a nodal agency for cross-border trade until it is opened for wider participation; harmonizing key rules governing access to transmission, including cross-border interconnections and pricing; reducing commercial barriers for electricity trade; developing a framework to address system imbalances related to cross-border trade; establishing bilateral mechanisms and a regional framework to resolve disputes; allowing open access initially for transmission network and later for distribution network; and developing a regional transmission plan and a harmonized grid code in the medium to long term. The paper also suggests possible changes required to the existing electricity legislations in individual countries to accommodate and enhance regional electricity trade. The paper concludes that economic power exchange would not happen without the appropriate policies and without harmonizing legal and regulatory frameworks in all the necessary systems. If left to bilateral trading, the status quo of a limited trading regime will leave the vast economic, reliability, and environmental benefits unrealized. Experience across the world shows that such legal and regulatory changes can be accomplished successfully.

Optimal Setting of FACTS Devices using Particle Swarm Optimization for ATC Enhancement in Deregulated Power System

Abstract In electricity supply industries, the word deregulation is disassembly of original structure and reassembly into another form for better efficiency, performance and to draw private sector investment. The major concerns in deregulated power market are transmission pricing, congestion management and Available Transfer Capability (ATC) that need to be dogged. Among these intriguing challenges, one that needs to be interrogated to provide assured open access transmission service is ATC. The way of improving ATC is either adding transmission facilities or using various FACTS devices. In this paper, our concern is incorporation of FACTS, a semiconductor based control devices to enhance the ATC of transmission system. Various FACTS devices like STATCOM, SSSC and UPFC are modeled by power flow equations and optimally set the FACTS parameters by particle swarm optimization (PSO) technique in such a way so as to enhance ATC in the deregulated electricity environment. This replaces the audacious job of erecting new transmission system or expanding the existing one. The non iterative, simple and fast Power Transfer Distribution Factors (PTDF) based sensitivity method is adopted to determine and enhance ATC on sample six bus system to prove the feasibility of ATC enhancement for bilateral and multilateral transactions.

Design of integral controller for Load Frequency Control of Static Synchronous Series Compensator and Capacitive Energy Source based multi area system consisting of diverse sources of generation employing Imperialistic Competition Algorithm

Abstract This paper presents the design of integral controller for Load Frequency Control (LFC) under deregulated environment having diverse sources of power generation employing Imperialistic Competition Algorithm (ICA). Static Synchronous Series Compensator (SSSC) along with Capacitive Energy Storage (CES) has also been proposed to further increase the dynamic performance of the system in terms of peak time, overshoot and settling time. The concept of soft computing techniques greatly helps in overcoming the disadvantages posed by the conventional controllers. Open transmission access and the evolving of more socialized companies for generation, transmission and distribution affects the formulation of LFC problem. So the traditional LFC system is modified to take into account the effect of bilateral contracts on the dynamics. Simulation results show that the Imperialistic Competition Algorithm based system employing Static Synchronous Series Compensator and Capacitive Energy Source has better dynamic performance over the system without these parameters.

Congestion management in power systems – A review

Abstract In the past few decades, restructuring has overtaken all possible domains including the electric supply industry. Restructuring has brought about considerable changes by the virtue of which electricity is now a commodity and has converted into deregulated one. Such a competitive market has paved way for innumerable participants. This has led to overloading and congestion of transmission lines. Moreover, open access transmission network has ingenerated a more intensified problem of congestion. Thus, congestion management in power systems is germane and of central importance to the power industry. In this paper a review work is carried out to unite all the publications in congestion management.

FDI (foreign direct investment) in wind energy sector in India: Testing the effectiveness of state policies using panel data

This paper examines the role of state level institutional differences in attracting FDI (foreign direct investment) in wind energy in India. The role of institutional differences is measured by means of constructing a policy index using five key policies in wind energy: feed-in-tariff, open access transmission, third party sale, banking, and wheeling charges. Panel data techniques are then employed to investigate the impact of the policy differences on FDI inflow in wind energy for eight Indian states that have significant resource potential over the seven year period (2004–05 to 2010–11) after controlling for several state-specific factors. The results indicate that state-specific policy index for wind energy is significant in attracting FDI in a state irrespective of whether control variables are included or not.

IJIREEICE - Electrical, Electronics, Instrumentation and Control

In deregulated power system due to the increase of power transactions in transmission open access the transmission cost allocation is one of the major problems. For each transaction the Transaction Impact Factors (TIFs) are developed for the allocation of the transmission transaction costs. The transmission Impact Factor gives the information about the real power flow in the transmission lines with the transacted power. This logical method provides the impact of the line flows without running power flow solutions when the amount of transacted power changes in real time. This proposed method is evaluated by considering bilateral and multilateral transactions. The results coming from the proposed method is compared with Megawatt Modulus (MM) method on sample six bus and IEEE 30 bus system.

Aumann Shapley Method for Congestion Cost Allocation in Multilateral Transactions Framework of Restructured Power Market

Deregulation of Electricity market has not only led to increase in competition among generators, but also reduced electricity prices. It has introduced several issues in the market; two of them are congestion management and market power. Due to open transmission access all the participants have equal right to access transmission network. However, they have to bear the costs incurred to accommodate their transaction. The cost allocation is still a problem to be tackled efficiently. The prevailing problem is how to allocate the congestion cost among the market participants. An efficient and fair allocation of congestion cost would result in smooth operation of transmission system. It also helps in tackling congestion and market power. This paper proposes a novel approach using Aumann Shapley (AS) method of game theory for congestion cost allocation in a deregulated electricity market. The results obtained using proposed method are compared with uplift and nodal pricing methods for IEEE 14 bus system, New En...

Walking the Wall

Walking the Wall

Implementation of Load Frequency Control of SSSC and CES Based Hydrothermal System under Open Market Scenario Employing Fuzzy Logic Controller

This paper presents the analysis of Static Synchronous Series Compensator (SSSC) and Capacitive Energy storage (CES) based on hydrothermal system under open market scenario employing fuzzy logic controller. The formulation of Load Frequency Control (LFC) problem has been greatly affected due to open transmission access and evolution of more socialized companies for generation, transmission and distribution. The traditional LFC has been modified by taking into account the concept of bilateral contracts. Attempt has also been made to incorporate the concept of SSSC and CES to further improve the performance of the system. A detailed representation of design of Fuzzy Logic Controller (FLC) has been represented and the results have been compared with those of dual mode controller. The results indeed demonstrate the superior working of FLC than that of dual mode controller and the system shows better response with respect to peak time, overshoot and settling time in the presence of FLC.

Allocation of Transaction Cost to Market Participants Using an Analytical Method in Deregulated Market

Transmission cost allocation is one of the major challenges in transmission open access faced by the electric power sector. The purpose of this work is to provide an analytical method for allocating transmission transaction cost in deregulated market. This research work provides a usage based transaction cost allocation method based on line-flow impact factor (LIF) which relates the power flow in each line with respect to transacted power for the given transaction. This method provides the impact of line flows without running iterative power flow solution and is well suited for real time applications. The proposed method is compared with the Newton–Raphson (NR) method of cost allocation on sample six bus and practical Indian utility 69 bus systems by considering multilateral transaction.