By Topic

Power Systems, IEEE Transactions on

Issue 1 • Date Feb. 2006

Filter Results

Displaying Results 1 - 25 of 68
  • Table of contents

    Publication Year: 2006 , Page(s): c1 - 2
    Save to Project icon | Request Permissions | PDF file iconPDF (50 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Power Systems publication information

    Publication Year: 2006 , Page(s): c2
    Save to Project icon | Request Permissions | PDF file iconPDF (43 KB)  
    Freely Available from IEEE
  • Nodal price control: a mechanism for transmission network cost allocation

    Publication Year: 2006 , Page(s): 3 - 10
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB) |  | HTML iconHTML  

    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. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A decoupled time-domain Simulation method via Invariant subspace partition for power system analysis

    Publication Year: 2006 , Page(s): 11 - 18
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB) |  | HTML iconHTML  

    A decoupled method is proposed to deal with time-domain simulation for power system dynamic analysis. Traditionally, there are two main categories of numerical integration methods: explicit methods and implicit methods. The implicit methods are numerically stable but require more computational time to solve the nonlinear equations, while explicit methods are relatively efficient but may cause a numerical stability problem. This paper proposes a new hybrid method to take advantage of both explicit and implicit methods based on the invariant subspace partition. The original power system equations are decoupled into two parts that correspond to the stiff and nonstiff subspaces. For the stiff invariant subspace, the implicit method is applied to achieve numerical stability, and the explicit method is employed to handle nonstiff invariant subspace for the computational efficiency. As a result, the new hybrid method is both numerically stable and efficient. The approach is demonstrated through New England 39-bus and IEEE 118-bus systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fast computation of voltage stability security margins using nonlinear programming techniques

    Publication Year: 2006 , Page(s): 19 - 27
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB) |  | HTML iconHTML  

    This paper presents a simple, fast, and efficient method for determining the maximum loading point (MLP) and the voltage stability security margin of electric power systems. The proposed method is based on nonlinear programming techniques. The MLP is accurately obtained after a few load change steps. The computational procedure involves two kinds of load changes. Initially, load increases toward the MLP are defined for minimizing an objective function based on sensitivities. In case an overestimated load increase drives the system outside the feasible (stable) operating region, another very simple optimization-based procedure aimed to minimize the power mismatches determines the load adjustment (curtailment) to pull the system back onto the feasibility boundary. Simulation results for small test to large realistic systems are shown to validate the proposed method. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A novel nucleolus-based loss allocation method in bilateral electricity markets

    Publication Year: 2006 , Page(s): 28 - 33
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (248 KB)  

    The situation of current research on power losses allocation in bilateral electricity markets is presented. Based on cooperative game theory, a novel nucleolus theory-based method for power losses allocation under the bilateral-transactions model is put forward and compared in detail with the Shapley-value-based allocation method. The impacts of different market players on network power losses are taken into account. With the new method, network power losses can be allocated to each transaction reasonably. The allocation results would not be affected by the sequence that each transaction is formed and be active. The method answers for the open, equal, and impartial principles of electricity market and can be easily understood and accepted by market players. Numerical tests validated the equity and validity of the method. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dynamic optimizations of Monte Carlo simulation to assess locational capacity, transmission, and market parameters

    Publication Year: 2006 , Page(s): 34 - 42
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (360 KB) |  | HTML iconHTML  

    Risk indices of loss-of-load expectation and loss-of-energy expectation were traditionally used to determine generation adequacy. However, because responsibility of generation installation and transmission upgrades rests with different entities, both generation and transmission need to be examined to evaluate the resource adequacy of today's deregulated power systems. Further, it is important to delineate the contribution to curtailments arising from insufficient installed capacity and bottlenecks in transmission system. Hence, risk-based planning and market decision-makings have to address both generation and transmission jointly. This paper presents a procedure to combine dynamic optimization and Monte Carlo simulation to generate a vector space of solution, from which optimal solutions for different objectives can then be easily obtained. Determining locational capacity and transmission requirements serves the example of such an application. This paper closes with a discussion on some possible changes to risk criteria. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Coordination between medium-term generation planning and short-term operation in electricity markets

    Publication Year: 2006 , Page(s): 43 - 52
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB) |  | HTML iconHTML  

    This paper analyzes the coordination between medium-term generation planning and short-term operation in electricity markets. This coordination is particularly important from a practical point of view in order to guarantee that certain aspects of the operation that arise in the medium-term level are explicitly taken into account: limited-energy resources and obligatory-use resources. Three different approaches are proposed in order to guarantee that short-term decisions made by a generation company are consistent with its operation objectives formulated from a medium-term perspective. These approaches make use of technical and economic signals to coordinate both time scopes: primal information, dual information, and resource-valuation functions. This paper presents the main advantages and drawbacks of the three approaches and applies them to a case study that uses a conjectural-variation-based representation of the market. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A classification approach for power distribution systems fault cause identification

    Publication Year: 2006 , Page(s): 53 - 60
    Cited by:  Papers (38)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (416 KB) |  | HTML iconHTML  

    Power distribution systems play an important role in modern society. When distribution system outages occur, fast and proper restorations are crucial to improve the quality of services and customer satisfaction. Proper usages of outage root cause identification tools are often essential for effective outage restorations. This paper reports on the investigation and results of two popular classification methods: logistic regression (LR) and artificial neural network (ANN) applied on power distribution fault cause identification. LR is seldom used in power distribution fault diagnosis, while ANN has been extensively used in power system reliability researches. This paper discusses the practical application problems, including data insufficiency, imbalanced data constitution, and threshold setting that are often faced in power distribution fault cause identification problems. Two major distribution fault types, tree and animal contact, are used to illustrate the characteristics and effectiveness of the investigated techniques. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A new optimal reactive power flow model in rectangular form and its solution by predictor corrector primal dual interior point method

    Publication Year: 2006 , Page(s): 61 - 67
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (250 KB) |  | HTML iconHTML  

    A new optimal reactive power flow (ORPF) model in rectangular form is proposed in this paper. In this model, the load tap changing (LTC) transformer branch is represented by an ideal transformer and its series impedance with a dummy node located between them. The voltages of the two sides of the ideal transformer are then used to replace the turn ratio of the LTC so that the ORPF model becomes quadratic. The Hessian matrices in this model are constants and need to be calculated only once in the entire optimal process, which speed up the calculation greatly. The solution of the ORPF problem by the predictor corrector primal dual interior point method is described in this paper. Two separate prototypes for the new and the conventional methods are developed in MATLAB in order to compare the performances. The results obtained from the implemented seven test systems ranging from 14 to 1338 buses indicate that the proposed method achieves a superior performance than the conventional rectangular coordinate-based ORPF. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Unit commitment by an enhanced simulated annealing algorithm

    Publication Year: 2006 , Page(s): 68 - 76
    Cited by:  Papers (80)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (296 KB) |  | HTML iconHTML  

    A new simulated annealing (SA) algorithm combined with a dynamic economic dispatch method has been developed for solving the short-term unit commitment (UC) problem. SA is used for the scheduling of the generating units, while a dynamic economic dispatch method is applied incorporating the ramp rate constraints in the solution of the UC problem. New rules concerning the tuning of the control parameters of the SA algorithm are proposed. Three alternative mechanisms for generating feasible trial solutions in the neighborhood of the current one, contributing to the reduction of the required CPU time, are also presented. The ramp rates are taken into account by performing either a backward or a forward sequence of conventional economic dispatches with modified limits on the generating units. The proposed algorithm is considerably fast and provides feasible near-optimal solutions. Numerical simulations have proved the effectiveness of the proposed algorithm in solving large UC problems within a reasonable execution time. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmission loss unbundling and allocation under pool electricity markets

    Publication Year: 2006 , Page(s): 77 - 84
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (424 KB) |  | HTML iconHTML  

    This paper presents a methodology based on the circuit theories for unbundling and allocation of transmission losses among the participants of a pool-based electricity market. Starting from a known operation point and using the basic network equations without additional assumptions, an expression of the branch losses based on nodal current injections is derived. Since the power flow equations and circuit theories are satisfied, the methodology turns explicit, in a natural way, separating the losses at each system branch and assigning the responsibility to the respective market participants. It means that the loss allocation of each branch, which is produced by each generator and consumer, is obtained. Extensions and strategies considering unsubsidized and predefined proportion-based loss allocation as well as issues related with the allocation fairness and transparency are also included. Comparisons with previous methods and validation tests of the proposed method are reported by using the IEEE Reliability Test System. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A unified approach for processing unbalanced conditions in transient stability calculations

    Publication Year: 2006 , Page(s): 85 - 90
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (208 KB) |  | HTML iconHTML  

    A unified approach has been proposed in the paper for processing unbalanced operating conditions in transient stability calculations. The suggested method combined advantages of both abc phase coordinates and 012 sequence coordinates. The former is used to describe faults since it is suitable to modeling simultaneous faults and the latter is used for time simulation for its sparse nature. Novel fault description and coordinate conversion formulation is presented. The equivalent positive sequence bus admittance matrix is derived for interface with generators in stability simulation. With the new method, the sequence network constitution can be avoided; multiple and simultaneous faults and element parameter unbalance can be simulated easily; and the sparse technology can still be applied for study efficiency. Computer test results show clearly the effectiveness and efficiency of the new method. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Identifying a balancing point for electricity transmission contracts

    Publication Year: 2006 , Page(s): 91 - 98
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (296 KB)  

    Electricity transmission contracts allocate scarce resources, allow hedging against locational price differences, and provide information to guide investment. However, ownership of transmission contracts might enhance market power of strategic generators. If the allocation mechanism for transmission contracts does not prevent generators from obtaining market power-enhancing contracts, explicit restrictions on owning transmission contracts might be required. To ensure that these restrictions do not interfere with the need to hedge for transmission price risk, one proposal is to define all transmission contracts to a balancing point at which energy is traded. Generators are only allowed to own transmission contracts toward this balancing point. Traders or load hedge the price risk from this balancing point to the location of load with transmission contracts. We propose an algorithm and apply it to the European electricity network to identify a balancing point that reduces market power of generation companies and is well connected. Market-level data or detailed information about demand are not required. The only critical input is assumptions on future transmission constraint patterns. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The new Chilean transmission charge scheme as compared with current allocation methods

    Publication Year: 2006 , Page(s): 99 - 107
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (344 KB) |  | HTML iconHTML  

    We describe the new method used in Chile to allocate transmission charges among generating companies and customers, as defined in Law 19 940 of March 2004 (also known as Ley Corta or Short Law). We show that the new Chilean transmission charge scheme is a hybrid based on marginal cost pricing, identification of use through economic benefits and flow identification methods, and last, a postage stamp to redistribute almost all the charges that customers have to pay. We also estimate the direct per kilowatthour charge that customers will pay and discuss its effect on location and expansion signals. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reliability and price risk assessment of a restructured power system with hybrid market structure

    Publication Year: 2006 , Page(s): 108 - 116
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB) |  | HTML iconHTML  

    In a restructured power system with hybrid market structure, generation companies and customers trade electricity and reserve either through a centralized power pool or by bilateral contracts based on their price and reliability offers and requirements. This results in difficulty in price and reliability management of such power systems. This paper presents techniques to evaluate both reliabilities and prices for the pool and bilateral customers in a hybrid power market. In these techniques, reliability and price models for the power pool and bilateral suppliers have been developed using reliability network equivalents to easily include various agreements among market participants. Customer responses to prices are modeled using customer damage functions. The reliability and price problems with and without considering agreements are formulated using improved optimal power flow techniques based on these models. The correlation between reliabilities and prices has been considered in the techniques. The modified IEEE Reliability Test System has been analyzed to illustrate the proposed techniques. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simultaneous solution of control system equations in EMTP

    Publication Year: 2006 , Page(s): 117 - 124
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1328 KB) |  | HTML iconHTML  

    The existing approach for solving control systems in the Electromagnetics Transients Program is to insert one-time-step delays for breaking feedback loops when one or more nonlinear functions is encountered. Although this approach may remain acceptable for several well-behaved cases, it provides a nonsimultaneous solution for a nonlinear system. Fast varying components may create instabilities in such a solution and/or simply end up in a wrong operating region. In some cases, it imposes severe limitations on the integration time step for minimizing delays. This paper presents a new Jacobian matrix-based formulation for eliminating numerical delays in the solution of control system equations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Two algorithms for obtaining sparse loop matrices

    Publication Year: 2006 , Page(s): 125 - 131
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB) |  | HTML iconHTML  

    This paper deals with the problem of obtaining a linearly independent set of loop matrix equations, whose nonzero pattern is as sparse as possible. Unlike existing procedures, based on trees and associated fundamental loops, the two algorithms proposed in this paper attempt to find as short as possible loops by means of systematic breadth-first searches. Linear independence of the resulting loops is assured by forcing each loop to contain a characteristic branch that cannot belong to future or past loops, respectively. Such a branch plays the role of links in fundamental loops, providing more flexibility in the way loops are closed. Experimental results on benchmark systems show that the proposed methods yield loop matrices that are much sparser than those provided by existing methods. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An oligopolistic model of an integrated market for energy and spinning reserve

    Publication Year: 2006 , Page(s): 132 - 142
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB) |  | HTML iconHTML  

    In this paper, a model for oligopolistic competition in electricity markets is presented. Most previous proposed models have been static and focused only on the energy market incentives for strategic behavior. In contrast, in this paper, a multiperiod market for energy and spinning reserve (SR) is considered. By including such factors, the competition among participants is modeled with more realism. Competition in the energy market is modeled by means of conjectured supply functions, while conjectured reserve-price response functions are used to consider the generators' ability to alter the SR prices. The resulting equilibrium problem is modeled in terms of complementarity conditions. Based upon a complementarity model, the opportunity cost between the energy and SR markets is derived for oligopolistic markets. The proposed model is illustrated by a six-node network using a dc approximation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analyzing oligopolistic electricity market using coevolutionary computation

    Publication Year: 2006 , Page(s): 143 - 152
    Cited by:  Papers (27)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (472 KB) |  | HTML iconHTML  

    This paper presents a new unified framework of electricity market analysis based on coevolutionary computation (CCEM) for both the one-shot and the repeated games of oligopolistic electricity markets. The standard Cournot model and the new Pareto improvement model are used. The linear and constant elasticity demand functions are considered. Case study shows that CCEM is highly efficient and can handle the nonlinear market models that are difficult to be handled by conventional methods. The framework presented in this paper can help to overcome the difficulties of demand function specification encountered by the Cournot models. CCEM is found to be an effective and powerful approach for electricity market analysis. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A unified three-phase transformer model for distribution load flow calculations

    Publication Year: 2006 , Page(s): 153 - 159
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (248 KB) |  | HTML iconHTML  

    This paper provides a unified method to model three-phase transformers for distribution system load flow calculations, especially when the matrix singularity caused by the transformer configuration arises. This paper shows that the singularity appears only in certain transformer admittance submatrices and only in certain transformer configurations. The unified method presented in this paper can solve the voltage/current equations in the forward/backward sweep algorithm for various types of transformer configurations, whether or not the corresponding admittance submatrices are singular. Comprehensive comparisons have been made between the proposed approach and other methods. Test results demonstrate the validity and effectiveness of the proposed method. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Network constraint impacts on the competitive electricity markets under supply-side strategic bidding

    Publication Year: 2006 , Page(s): 160 - 170
    Cited by:  Papers (26)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB) |  | HTML iconHTML  

    In a competitive electricity market, the oligopoly structure of the market and the network constraints may produce results far from the perfect competition. This paper presents a comprehensive approach to evaluate the performances of the electricity markets with network representation in presence of bidding behavior of the producers in a pool system. A supply function strategic bidding model for the producers is introduced, and then different scenarios in terms of bidding behavior and network constraints are studied and compared on the basis of a set of microeconomic metrics. The aim of the paper is to assess, throughout a set of proper indices, the level of competition in a network-constrained market considering strategic behavior of the producers. The approach proposed gives the possibility to assess the different weight of strategic behavior of the producers and of the network constraints in distorting the market performances from its perfect competition equilibrium. From such an analysis, the worsening of the market efficiency and performances, due to the joint effects of the nonperfect competition and the network constraints, may be assessed and quantified, providing information on the adequacy of the grid considered for accommodating a competitive market. The exploitation of the proposed metrics for the market analysis is shown with reference to the IEEE 30-bus test system with demand elasticity explicitly represented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Continuation-based quasi-steady-state analysis

    Publication Year: 2006 , Page(s): 171 - 179
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    This paper presents continuation-based quasi-steady-state (CQSS) analysis to approximate the long-term evolution by tracing successive equilibrium points. Applying the parameterized continuation technique to QSS simulation can provide good convergence when the system approaches the bifurcation points. Parameterization of the load exponents through continuation method makes it possible to simulate dynamic load recovery models in the system without numerical integration. The tap dynamics are also included in the CQSS analysis. The simulation results with the modified WECC 179-bus system are described in order to demonstrate the overall methodology. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal price and quantity determination for retail electric power contracts

    Publication Year: 2006 , Page(s): 180 - 187
    Cited by:  Papers (28)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (376 KB) |  | HTML iconHTML  

    Considering the viewpoint of a retailer, this paper analyzes the problem of setting up contracts on both the supplier and end-user sides to maximize profits while maintaining an acceptable level of settlement risk. The proposed stochastic optimization model can assist retailers with these efforts and guide them in their contractual arrangements. A realistic example illustrates the capabilities of the methodology proposed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Bulk electric system well-being analysis using sequential Monte Carlo simulation

    Publication Year: 2006 , Page(s): 188 - 193
    Cited by:  Papers (29)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB) |  | HTML iconHTML  

    There is growing interest in combining deterministic considerations with probabilistic assessment in order to evaluate the "system well-being" of a composite generation and transmission system and to evaluate the likelihood not only of entering a complete failure state but also the likelihood of being very close to trouble. This paper presents bulk electric system well-being analysis using sequential Monte Carlo simulation. This approach provides accurate frequency and duration assessments and the index probability distributions associated with the mean values. The basic N-1 security criterion is used as the deterministic requirement for incorporating a deterministic consideration in a probabilistic assessment to monitor system well-being. The results shown in this paper indicate that the system well-being concept can provide comprehensive knowledge on what the degree of system vulnerability might be under a particular system condition. The basic concepts and their application in composite power system well-being analysis are illustrated by application to a small practical test system. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

Covers the requirements, planning, analysis, reliability, operation, and economics of electric generating, transmission, and distribution systems for general industrial, commercial, public, and domestic consumption.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Antonio J. Conejo
The Ohio State University