Available Transfer Capability Calculation Research Articles

Calculation of Available Transfer Capability Using Hybrid Chaotic Selfish Herd Optimizer and 24 Hours RES-thermal Scheduling

Calculation of Available Transfer Capability Using Hybrid Chaotic Selfish Herd Optimizer and 24 Hours RES-thermal Scheduling

A SSSC optimal configuration method to enhance available transfer capability considering multi‐wind farm access

AbstractIn the context of electricity market, the heavy load of some inter‐provincial and intra‐provincial lines limits available transfer capability (ATC). As a series compensation device, static synchronous series compensator (SSSC) can reallocate the power flow of adjacent lines. In order to maximize the inter‐regional ATC, a two‐stage optimal SSSC allocation method considering the uncertainty and correlation of multi‐wind farm is proposed. Firstly, the initial wind power scenarios are generated based on latin hypercube sampling (LHS) and reduced by the improved iterative self‐organizing data analysis techniques algorithm (I‐ISODATA). Then, a multi‐objective optimization model is constructed with the maximum expected power flow transfer entropy (PFTE) and minimum expected SSSC investment cost in all typical wind power scenarios, and non‐dominated sorting genetic algorithm‐II (NSGA‐II) method is used to determine the location of SSSC. In addition, based on the reduced wind power scenarios, the ATC calculation model containing SSSC is constructed, and the modern interior point method is used to determine the control parameters and configuration capacity of SSSC. Finally, based on the improved IEEE39 and IEEE118 node systems, case study proves that the proposed model can determine the optimal SSSC configuration scheme and significantly improves the ATC.

A New Hybrid Method to Assess Available Transfer Capability in AC–DC Networks Using the Wind Power Plant Interconnection

This article presents a very effective and exact technique for evaluating dynamic available transfer capability (ATC) using a fast differential equation power flow (DEPF) and Newton–Raphson–Seydel, taking into account the initial contingency (n-1) scenarios and the normal system condition. We indicated that instead of simply inverting the Jacobian matrix, the inverse computation time of the DEPF may be substantially decreased by inverting the submatrices. A hybrid technique was developed for Dynamic ATC calculation using a mixture of the static and dynamic methods. Installing the high voltage direct current (HVdc) line is taken into account in the ATC calculations because HVdc is the backbone of the future transmission network. The challenge of integrating wind power plants and big loads into the future network is also explored in this article. In an attempt to rectify earlier techniques, an estimate of the potential energy boundary surface was also used in conjunction to assess transient stability. This technique was effectively applied on IEEE 39 bus, IEEE 118 bus, Iowa State 145-bus, IEEE 300-bus, the east of Iran (1153 buses), and Khorasan network (4438 buses) systems for different bilateral/ multilateral transactions.

Assessment of the influence of wind energy incorporated capacity benefit margin in ATC computation

Available transfer capability (ATC) is an important metric used to measure the techno-economic viability of the transmission networks. Several methods have been presented in literature for ATC assessment, however, only some few articles incorporate CBM in ATC calculation and those few papers only considered conventional power generation sources in CBM evaluation. CBM is a function of the reliability of generating units. This paper presents the inter-area CBM calculation in the presence of wind energy source using graph theory technique and the results are incorporated in ATC computation using repeated power flow. CBM is incorporated in ATC computation as non-recallable and recallable power transfers. The results with and without CBM incorporation, in the presence of wind power system, are compared. The contribution of the paper is to study the influence of wind power (WP) integrated CBM on ATC evaluation. The results showed that the incorporation of CBM, in the presence of renewable energy, has a significant influence on ATC, without which ATC would be inaccurately estimated. Simulations using IEEE 24-Bus RTS is used to implement the proposed approach. This approach can be employed by transmission operators to assess the technoeconomic viability of the power network for possible power transactions.

Available transfer capability evaluation in electricity-dominated integrated hybrid energy systems with uncertain wind power: An interval optimization solution

Available transfer capability (ATC) is widely used in the deregulated electricity market to ensure secure and reliable power trading among market participants. However, most conventional ATC calculation methods do not fully consider the impacts of renewable energy integration and the close interdependency among electricity, natural gas, and district heating networks. To overcome these challenges, this work evaluates the ATC in an electricity-gas-heating integrated hybrid energy system (IHES) in a more practical manner by considering renewable energy uncertainties. In the proposed approach, the detailed models of electricity, natural gas, and district heating infrastructures are provided and their operational constraints are fully respected. To reduce input data requirements, the wind power uncertainty is modeled as interval bounds instead of detailed probability distribution functions (PDFs). Consequently, this interval optimization-based ATC model is converted to two sub-problems to solve the lower and upper boundaries of the objective function value. The proposed approach provides a quantitative approach to numerically calculate the impact on ATC from various components in an IHES. Simulation results on the IHES 5–7-6 and the IHES 118–96-6 + 32 systems validate its effectiveness.

An efficient differential equation load flow method to assess dynamic available transfer capability with wind farms

Differential equation load flow (DELF) is an innovative approach to convert a load flow model to a fictitious dynamic system. DELF solves the entire time-domain analysis of a dynamic system trajectory rather than solving load flow equations repeatedly in a set of conditions. The static available transfer capability (ATC) determination algorithm is specified through a method called the approximation of the path of the minimum distance method. In this method, instead of a repeated power flow, only three system operating points are used. An estimation of the potential energy boundary surface was also employed to determine the transient stability in an attempt to correct previous methods. A combination of static method and transient stability led to a combined approach to dynamic ATC computation. This paper proposes a truly effective and precise method to assess Dynamic ATC using the differential equation load flow considering the first contingency (n − 1) situations and the intact system condition. For various multilateral and bilateral transactions, this method was successfully implemented on 39, 118- and 300-bus IEEE, 145-bus Iowa-State, the west of Iran (1153-bus), and Mashhad MV distribution network (4438-buses) systems. The results showed a better suitability, a higher speed and accuracy than other dynamic ATC methods.

Available Transfer Capability Enhancement by FACTS Devices Using Metaheuristic Evolutionary Particle Swarm Optimization (MEEPSO) Technique

Energy power flows are an important factor to be calculated and, thus, are needed to be enhanced in an electrical generation system. It is very necessary to optimally locate the Flexible Alternating Current Transmission Systems (FACTS) devices and improve the Available Transfer Capability (ATC) of the power transmission lines. It relieves the congestion of the system and increases the flow of power. This research study has been accomplished in two stages: optimization of location of FACTS device by the novel Sensitivity and Power loss-based Congestion Reduction (SPCR) method and the calculation of ATC using the proposed Metaheuristic Evolutionary Particle Swarm Optimization (MEEPSO) technique. The Thyristor Controlled Series Capacitor (TCSC) is used as a FACTS device to control the reactance of power transmission line. The effectiveness of the proposed methods is validated, utilizing the six bus as well as 30 bus system. The acquired outcomes are contrasted with conventional ACPTDF and DCPTDF procedures. These values are determined with the assistance of MATLAB version 2017 on the Intel Core i5 framework by taking two-sided exchanges and they are contrasted and values determined with the assistance of Power World Simulator (PWS) programming.

Impact of wind power generation on ATC calculation with uncertain equal load

Available transfer capability (ATC) is very important for system operators for a fair and transparent electricity market. There are many methods to calculate and to improve the ATC value in the power system. Due to green energy focus across the globe, renewable energy integration to the system to improve the ATC value need to be established. Lots of literature have been published on wind power integration to improve ATC value using active power support. During highly loaded conditions, reactive power plays an important role. In this paper, active as well as reactive power of wind turbine generation for ATC calculation has been considered. The reactive power limit has been considered based on the capability curve of the wind turbine generator. Real-time wind speed data for wind power output calculation are taken. The impact analysis of wind power generation on ATC variation under normal as well as contingency cases has been carried out. The effectiveness of the proposed method is tested on the IEEE-30 bus system.

A Graph-Theoretic Approach to Capacity Benefit Margin Calculation for Large Multiarea Power Systems

In a deregulated power market, independent system operators exchange information related to the available transfer capability (ATC) of their respective areas for efficient power system operation. Accurate ATC calculation is important for efficient market operations. Among the parameters required to calculate ATC, the capacity benefit margin (CBM) is an important one. CBM represents the interarea tie-lines capacity reserved in order to have access to external generation in an event of power supply shortage. This paper proposes a new technique for CBM evaluation using graph theory concepts. The proposed technique can be used as an effective tool to solve the CBM problem for large multiarea power systems which are not fully connected and may have multiple deficient areas, unlike previous approaches which considered only fully connected areas with only one deficient area. The IEEE 24-bus reliability test system is employed to implement the proposed method. A performance analysis of the proposed technique shows that it can find a feasible solution efficiently.

Evaluation and Analysis of Available Transfer Capability in Deregulated Power System Environment

Reliability of network is need of the hour in the present power system market and is constrained by capability of the network. The network calculations are performed using accurate and high efficient strategies. In order to perform power transactions in the system, the computation of available transfer capability is essential which a metric of capability of the system. Generally, effect wattless power is not taken into account in the methodologies for computation of linear available transfer capability. In this paper, a methodology which considers the reactive power flows for enhancement of linear ATC is presented. In order to perform analysis theoretically, a standard IEEE 3 bus system is considered. Another case study i.e., 14 bus system available in IEEE test systems is used for simulation analysis. FACTS technology is incorporated in the existing system in order to enhance capability of the network. To facilitate transfer maximum power in the system, an optimal power-flow-based ATC enhancement model is formulated and presented along with simulation results. Studies based on the IEEE 3-bus system and 14-bus systems with TCSC demonstrate the effectiveness of FACTS control on ATC enhancement.

ATC Evaluation In A Deregulated Power System

Restructured power system helps to meet the active power requirements of the consumers in an effective way. In an Independent System Operator (ISO) model of restructured power system, Available Transfer Capability (ATC) is calculated so as to determine how much extra power can be injected into one site apart from base consumption. ATC computation plays a significant role during power transactions because it helps the participants to schedule their transaction more effectively and quickly. This paper mainly focuses on ATC calculation using linear sensitivity factors for normal mode and line outage mode.

Computation of Available Transfer Capability in Electrical Transmission System - A Review

Computation of Available Transfer Capability in Electrical Transmission System - A Review

Estimation of dynamic available transfer capability including Hopf bifurcation limit using step by step algorithm

The electric power industries, all over the world, are changing to a new deregulated environment. In a deregulated environment, calculation of available transfer capability (ATC) of transmission system is an important issue. ATC calculated with dynamic stability limit is referred as dynamic ATC (DATC). The Hopf bifurcation limit, associated with dynamic voltage instability is considered in this paper as limit for ATC calculation. A new step by step algorithm for finding Hopf bifurcation point in DATC problem has been developed. Dynamic ATC is calculated for bilateral and multilateral transaction using proposed approach. The proposed approach is tested on WSCC 3 machine 9-bus system and New England 10 machine 39-bus system. This is implemented for two load scenarios namely as static and dynamic (induction machine model) load. The results are compared with existing sequential quadratic programming method. Test results show the accuracy and effectiveness of the proposed method in estimating ATC value.

Determination of ATC Using DCPTDFs Based Approach in Deregulated Market

Deregulated electricity industry aims to create a competition in market to trade electricity, which gives new opportunities to deal with technical challenges of market participants and power system researchers. The benefits are efficient capacity expansion planning, cheaper electricity, cost minimization, and better services. For better transmission services support in electricity industry and full utilization of transmission assets, Available Transfer Capability (ATC)must be calculated. Available transfer capability (ATC) of transmissionnetwork is the extra amount of power transfer that can betransmitted between the buyer bus and seller bus without any loss ofsecurity. For proper operations of system under the varioustransactions, ATC calculations must be fast andaccurate enough. In this paper by using DCPTDF scheme the ATC is calculatedwith and without line contingency caseand then the corresponding values of ATC are compared. The multiple line contingencies and their effecton the value of ATC are shown. The above said methodology is implemented on IEEE 24-bus test system.

Available transfer capability evaluation and enhancement using various FACTS controllers: Special focus on system security

Abstract Nowadays, because of the deregulation of the power industry the continuous increase of the load increases the necessity of calculation of available transfer capability (ATC) of a system to analyze the system security. With this calculation, the scheduling of generator can be decided to decrease the system severity. Further, constructing new transmission lines, new substations are very cost effective to meet the increasing load and to increase the transfer capability. Hence, an alternative way to increase the transfer capability is use of flexible ac transmission system (FACTS) controllers. In this paper, SSSC, STACOM and UPFC are considered to show the effect of these controllers in enhancing system ATC. For this, a novel current based modeling and optimal location strategy of these controllers are presented. The proposed methodology is tested on standard IEEE-30 bus and IEEE-57 bus test systems with supporting numerical and graphical results.

Iterative Distributed Algorithms for Real-Time Available Transfer Capability Assessment of Multiarea Power Systems

This paper studies iterative distributed algorithms for real-time available transfer capability (ATC) assessment in energy management systems of multiarea power systems. Since ATC calculations can be modeled as a special nonlinear optimal power-flow problem, iterative decomposition-coordination approaches based on constrained augmented Lagrangian methods can be applied. One special distributed scheme, called the auxiliary problem principle method, will be studied for distributed ATC assessment in this paper. A computation framework of this distributed algorithm is investigated. System partition with nonoverlapping and boundary sub-systems will also be studied. Simulations of several IEEE test systems will be conducted to validate the feasibility and the correctness of this distributed ATC. In addition, the real-time monitoring and reaction mechanism of this distributed algorithm will also be demonstrated by numerical experiments.

Numerical bifurcation and its application in computation of available transfer capability

Numerical bifurcation analysis techniques are very powerful and efficient in physics, biology, engineering, and economics. This paper mainly discusses its application in computation of available transfer capability (ATC) among the specific interface in AC–DC hybrid power grid. Considering the load as a parameter, which implies the load increment at any bus and the specified generation schedule, the saddle node bifurcation and the Hopf bifurcation have been used for static and dynamic ATC determination respectively. The proposed method has been applied to a modified WSCC 9-bus AC–DC power system for the ATC determination. The impact of the method has also been discussed.

Available Transfer Capability (ATC) as Index for Transmission Network Performance – A Case Study of Nigerian 330kV Transmission Grid

Performance measurement of transmission system is vital to proper planning and operations of power systems in the presence of deregulation. Degree of performance is often measured by technical and financial key performance indicators (KPIs) often determined by unavailability, quality of supply and energy lost. This paper implement a novel method, Hybridized continuous repeated power flow (HCR-PF) to compute inter-area ATC and gives a method based on computed ATC to determine the transmission efficiency by measuring the transmission system transfer efficiency in terms of available transfer capability. Available Transmission Transfer Efficiency (ATTE) expresses the percentage of real power received resulting from inter-area available power transfer. The results show that HCR-PF provides a good approximate alternative to ATC computation which is validated using IEEE 30 bus test network. The Tie line (physical path) performance is obtained by calculating the required sending end quantities with specified receiving end ATC and the receiving end power circle diagram.

Using the UPFC and GUPFC Controllers to Maximize Available Transfer Capability (ATC)

This paper focuses on studying the effect of the unified power flow controller (UPFC) and generalized unified power flow controller (GUPFC) to maximize the Available Transfer Capability (ATC). The normalized sensitivity factors technique is used, can be approximately computed, to determine the ATC of a test system, considering a variety of system limits. The basic Voltage Stability Constrain Optimal Power Flow (VSC-OPF) solution that does not consider contingencies is used for determining the sensitivity of power flows with respect to the critical loading parameter. Then, based on this solution and assuming a small variation of the loading parameter, compute the power flows again by solving critical power flows function. Then the sensitivity of system loading factor and N-1 contingency criteria technique is used to determine an optimal location of the UPFC and GUPFC controller. Finally, using proper models of the UPFC and GUPFC controllers, the effects of this Flexible AC Transmission System (FACTS) controller on the system ATC are studied. The IEEE 57- bus and 118-bus is used as the test system for validity, computing the system ATC for a given generation and loading pattern. All realistic control limits, as well as voltage dependent loads, are used in the ATC computation, with and without FACTS controller. The GUPFC can so strong influence the system in controlling or enhancement the ATC as good as power flow possible is compared with the UPFC. Keyword: UPFC, GUPFC. ATC, loading parameter, VSC-OPF

Determination of available transfer capability with implication of cascading collapse uncertainty

Available transfer capability (ATC) provides important information for power marketers and planning sectors in restructured power systems. The stochastic nature of power system behaviour, however, made ATC determination a difficult and complicated task. A stochastic framework has been established for ATC calculation with implication of uncertainties in transmission failures, hourly peak loads and system cascading collapse. The proposed ATC calculation framework is based on parametric bootstrap technique which enables generating random samples of system operating condition with uncertainty at a predefined confidence interval. The IEEE RTS-96 network is employed to demonstrate the effectiveness of the proposed framework. The results presented indicate the significant impact of uncertainties on ATC value.