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Power Systems, IEEE Transactions on

Issue 1 • Date Feb. 2009

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Displaying Results 1 - 25 of 59
  • Table of contents

    Publication Year: 2009 , Page(s): C1 - 2
    Save to Project icon | Request Permissions | PDF file iconPDF (49 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Power Systems publication information

    Publication Year: 2009 , Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (39 KB)  
    Freely Available from IEEE
  • An Energy Conversion Laboratory Using Industrial-Grade Equipment

    Publication Year: 2009 , Page(s): 3 - 11
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1131 KB) |  | HTML iconHTML  

    Laboratory experiences are an important component of the education of engineering students. Rotating machinery laboratories assist with the visualization of the three-dimensional and rotating equipment. Contemporary use of rotating machines in industry often includes adjustable speed drives and digital controllers. Additionally, instrumentation is used to feedback electrical and mechanical variables to the drives and controls. Using an equipment grant from an industrial automation manufacturer, cost-effective laboratory workstations have been developed. Industrial-grade equipment is not designed for student experimentation but was adapted for this use. The workstations described in this paper incorporate modern power electronic-based drives and motors, electrical and mechanical sensors, and a computer-based control system with data acquisition. The advantages of these workstations include cost-effectiveness and the use of actual industrial devices that students might encounter in industry. Additionally, the workstations can be accessed by remote users, enabling off-campus students to also perform experiments on the workstations. The paper includes details of the workstation and its components, the data acquisition and control system, and sample experimental results. View full abstract»

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  • Cache Energy Control for Storage: Power System Integration and Education Based on Analogies Derived From Computer Engineering

    Publication Year: 2009 , Page(s): 12 - 19
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (341 KB) |  | HTML iconHTML  

    Energy storage is an enabling technology for power system integration of renewable sources, while data storage enables computer system integration. In this paper, a functional analogy relating energy and data storage is derived. Battery or hydrogen storage can provide large energy capacity similar to a hard disk providing large data capacity. Supercapacitors or flywheels provide fast and frequent access to cache energy similar to the computer's RAM providing fast and frequent access to data. In analogy to computer engineering, a cache control that coordinates the operation of a multilevel storage consisting of such complementary capacity and access-oriented storage technologies is designed. It is illustrated how for an industrial distributed energy system with renewable generation, local load, fueling station, and connections to the electricity and gas distribution networks, the cache control provides energy management to support a modular plug-and-play-like system integration. The benefit of the analogy in education is evaluated on a representative sample of electrical engineering students at the University of Washington. While familiar with computing, students do not typically have the same level of exposure to power engineering. The understanding of distributed energy systems concepts is shown to improve thanks to this bridging analogy between computer and power engineering. View full abstract»

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  • Applying Wavelets to Short-Term Load Forecasting Using PSO-Based Neural Networks

    Publication Year: 2009 , Page(s): 20 - 27
    Cited by:  Papers (61)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (967 KB) |  | HTML iconHTML  

    The paper addresses the problem of predicting hourly load demand using adaptive artificial neural networks (ANNs). A particle swarm optimization (PSO) algorithm is employed to adjust the network's weights in the training phase of the ANNs. The advantage of using a PSO algorithm over other conventional training algorithms such as the back-propagation (BP) is that potential solutions will be flown through the problem hyperspace with accelerated movement towards the best solution. Thus the training phase should result in obtaining the weights configuration associated with the minimum output error. Data are wavelet transformed during the preprocessing stage and then inserted into the neural network to extract redundant information from the load curve. This results in better load characterization which creates a more reliable forecasting model. The transformed data of historical load and weather information were trained and tested over various periods of time. The generalized error estimation is done by using the reverse part of the data as a ldquotestrdquo set. The results were compared with traditional BP algorithm and offered a high forecasting precision. View full abstract»

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  • Radial Power Flow Tolerance Analysis by Interval Constraint Propagation

    Publication Year: 2009 , Page(s): 28 - 39
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (588 KB) |  | HTML iconHTML  

    Many applications in modern distribution management systems (DMS) need the support of robust and reliable radial power flow analysis. In this connection, although radial power flow solution algorithms are widely proposed in the literature, their application is often complicated by the presence of uncertainties affecting the distribution network operation. The effect of these uncertainties could affect the power flow solution to a considerable extent. A comprehensive tolerance analysis is therefore required in order to incorporate the effect of data uncertainties into power flow analysis. To address this problem, in this paper the employment of interval constraint propagation (ICP) is proposed. ICP is an effective technique for refining enclosures to solutions of nonlinear systems of equations by merging interval mathematic and constraint propagation techniques. Several numerical results are presented and discussed in order to assess the effectiveness of the proposed methodology as an alternative to sampling-based technique, in radial power flow analysis. View full abstract»

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  • Using Copulas for Modeling Stochastic Dependence in Power System Uncertainty Analysis

    Publication Year: 2009 , Page(s): 40 - 49
    Cited by:  Papers (36)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1611 KB) |  | HTML iconHTML  

    The increasing penetration of renewable generation in power systems necessitates the modeling of this stochastic system infeed in operation and planning studies. The system analysis leads to multivariate uncertainty analysis problems, involving non-Normal correlated random variables. In this context, the modeling of stochastic dependence is paramount for obtaining accurate results; it corresponds to the concurrent behavior of the random variables, having a major impact to the aggregate uncertainty (in problems where the random variables correspond to spatially spread stochastic infeeds) or their evolution in time (in problems where the random variables correspond to infeeds over specific time-periods). In order to investigate, measure and model stochastic dependence, one should transform all different random variables to a common domain, the rank/uniform domain, by applying the cumulative distribution function transformation. In this domain, special functions, copulae, can be used for modeling dependence. In this contribution the basic theory concerning the use of these functions for dependence modeling is presented and focus is given on a basic function, the Normal copula. The case study shows the application of the technique for the study of the large-scale integration of wind power in the Netherlands. View full abstract»

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  • Continuous Newton's Method for Power Flow Analysis

    Publication Year: 2009 , Page(s): 50 - 57
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (526 KB) |  | HTML iconHTML  

    This paper describes the application of the continuous Newton's method to the power flow problem. This method basically consists in formulating the power flow problem as a set of autonomous ordinary differential equations. Based on this formal analogy, we propose an entire family of numerically efficient algorithms for solving ill-conditioned or badly-initialized power flow cases. The paper also shows that the classical Newton-Raphson's method and most robust power flow techniques proposed in the literature are particular cases of the proposed formulation. An example based on a 1254-bus model of the UCTE system is presented and discussed. View full abstract»

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  • Using State Diagrams for Modeling Maintenance of Deteriorating Systems

    Publication Year: 2009 , Page(s): 58 - 66
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (263 KB) |  | HTML iconHTML  

    This paper discusses the use of state diagrams in maintenance modeling. These diagrams frequently illustrate deterioration, inspections and maintenance. Mathematically, the state diagram can be represented by a Markov process. The paper discusses the properties of such a Markov process. They are compared with the maintenance situation in the real world. It is shown that some properties make the model inconsistent with reality especially in cases where a maintenance policy with nonperiodic inspections is modeled. A numerical example is provided that shows that these model properties result in modeling errors. The presented results make it clear that the common practice of using Markov processes based on state diagrams must be judged critically when they are used for modeling certain maintenance strategies. View full abstract»

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  • An Oligopoly Model for Medium-Term Power Planning in a Liberalized Electricity Market

    Publication Year: 2009 , Page(s): 67 - 77
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (780 KB) |  | HTML iconHTML  

    We address the problem of finding optimal medium- term generation policies for a specific generation company by modeling the supply side of a liberalized electricity market. The model assumes a noncooperative oligopoly and determines the joint optimal generation policies of all market generators, taking into account hydro, market, and system uncertainties. We propose an endogenous function of market price with respect to load duration where the choice of fuel and technology influences both the average and range of variation of the medium-term market price. We assume an inelastic demand represented by the load-duration curve, which is matched using the Bloom and Gallant formulation. This accounts for unit outages without using scenarios, which are reserved for modeling other uncertainties such as a latent price variable and the hydro inflows. The equilibrium is solved using the Nikaido-Isoda relaxation algorithm, which enables a series of multistage cubic stochastic programming models to be solved. In order to deal with the large number of load matching constraints, we use a heuristic which allows us to generate only those constraints that will presumably be active at the optimal solution. The model is calibrated to the Spanish electricity market using historical price and generation data. View full abstract»

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  • Power System Risk Assessment and Control in a Multiobjective Framework

    Publication Year: 2009 , Page(s): 78 - 85
    Cited by:  Papers (24)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (738 KB) |  | HTML iconHTML  

    Traditional online security assessment determines whether the system is secure or not, but how secure or insecure is not explicitly indicated. This paper develops probabilistic indices, risk, to assess real-time power system security level. Risk captures not only event likelihood, but also consequence. System security level associated with low voltage and overload can be optimally controlled, using the NSGA multiobjective optimization method. A security diagram is used to visualize operating conditions in a way that enables both risk-based and traditional deterministic views. An index for cascading overloads is used to evaluate the Pareto optimal solutions. This paper shows that the multiobjective approach results in less risky and less costly operating conditions, and it provides a practical algorithm for implementation. The IEEE 24-bus RTS-1996 system is analyzed to show that risk-based system security control results in lower risk, lower cost, and less exposure to cascading outages. View full abstract»

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  • Identifying Power Flow Control Infeasibilities in Large-Scale Power System Models

    Publication Year: 2009 , Page(s): 86 - 95
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (359 KB) |  | HTML iconHTML  

    This paper describes a methodology to identify potential conflicts among power flow control devices that may slow down or impair convergence. The proposed methodology is based on the eigenvalue analysis of the sparse Jacobian matrix associated with the Newton power flow with controls. Practically identical results are obtained from a smaller control sensitivity matrix. The implementation in a power flow program has been tested using both small- and large-scale systems. The results presented validate and clearly indicate the effectiveness of the proposed technique. View full abstract»

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  • Worst-Case Interdiction Analysis of Large-Scale Electric Power Grids

    Publication Year: 2009 , Page(s): 96 - 104
    Cited by:  Papers (28)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (238 KB) |  | HTML iconHTML  

    This paper generalizes Benders decomposition to maximize a nonconcave objective function and uses that decomposition to solve an ldquoelectric power grid interdiction problem.rdquo Under one empirically verified assumption, the solution to this bilevel optimization problem identifies a set of components, limited by cardinality or ldquointerdiction resource,rdquo whose destruction maximizes economic losses to customers (and can thereby guide defensive measures). The decomposition subproblem typically incorporates a set of DC optimal power-flow models that cover various states of repair after an attack, along with a load-duration curve. Test problems describe a regional power grid in the United States with approximately 5000 buses, 6000 lines, and 500 generators. Solution time on a 2-GHz personal computer is approximately one hour. View full abstract»

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  • Tighter Approximated MILP Formulations for Unit Commitment Problems

    Publication Year: 2009 , Page(s): 105 - 113
    Cited by:  Papers (32)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (598 KB) |  | HTML iconHTML  

    The short-term unit commitment (UC) problem in hydrothermal power generation is a large-scale, mixed-integer nonlinear program, which is difficult to solve efficiently, especially for large-scale instances. It is possible to approximate the nonlinear objective function of the problem by means of piecewise-linear functions, so that UC can be approximated by an mixed-integer linear program (MILP); applying the available efficient general-purpose MILP solvers to the resulting formulations, good quality solutions can be obtained in a relatively short amount of time. We build on this approach, presenting a novel way to approximating the nonlinear objective function based on a recently developed class of valid inequalities for the problem, called ldquoperspective cuts.rdquo At least for many realistic instances of a general basic formulation of UC, an MILP-based heuristic obtains comparable or slightly better solutions in less time when employing the new approach rather than the standard piecewise linearizations, while being not more difficult to implement and use. Furthermore, ldquodynamicrdquo formulations, whereby the approximation is iteratively improved, provide even better results if the approximation is appropriately controlled. View full abstract»

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  • Estimating the Spinning Reserve Requirements in Systems With Significant Wind Power Generation Penetration

    Publication Year: 2009 , Page(s): 114 - 124
    Cited by:  Papers (114)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (557 KB) |  | HTML iconHTML  

    Spinning reserve (SR) allows system operators to compensate for unpredictable imbalances between load and generation caused by sudden outages of generating units, errors in load forecasting or unexpected deviations by generating units from their production schedules. As the proportion of power produced by wind farms increases, it becomes more difficult to predict accurately the total amount of power injected by all generators into the power system. This added uncertainty must be taken into account when setting the requirement for SR. This paper proposes a technique to calculate the optimal amount of SR that the system operator should provide to be able to respond not only to generation outages but also to errors in the forecasts for load and wind power production. Using a Monte Carlo simulation, the proposed technique for setting the SR requirements is then compared with the traditional deterministic criterion (i.e., the capacity of the largest online infeed), an approach to cope with wind imbalances and an approach that combines the traditional criterion with the approach to cope with wind imbalances. The results show that, contrary to what is commonly believed, an increased wind power penetration does not necessarily require larger amounts of SR. View full abstract»

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  • Admissible Locational Marginal Prices via Laplacian Structure in Network Constraints

    Publication Year: 2009 , Page(s): 125 - 133
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (378 KB) |  | HTML iconHTML  

    Standard computations reveal that locational marginal prices (LMPs), being Lagrange multipliers in an optimization problem, must lie in the null space of a Jacobian matrix evaluated at the optimal power flow solution, augmented by columns associated with active line flow limits. The impact of network power flow and active line limit constraints is to confine the LMPs in a subspace that satisfies necessary conditions for optimality. Optimal market clearing can then proceed as a minimization over offer curves confined to admissible LMPs in this subspace. When no line limits are active and losses neglected (e.g. in a dc power flow representation), the matrix in question has a generalized Laplacian structure, and admits only a vector of all equal elements in its null space (verifying the well-known equal incremental cost condition). As line flow limits become active, the null space grows in dimension. Among the phenomena of interest as the dimension of admissible LMPs grows is that of ldquoload pocketsrdquo; that is, admissible LMP vectors that can show patterns in which buses partition into zones of approximately equal LMPs, with significant differences between zones. This paper explores an approach to admissible LMP calculation that isolates the topological role of active line flow constraints, independent of offer curve prices. Identification of this admissible subspace can then greatly facilitate computations such as clustering to identify potential zones of differentiated LMPs. View full abstract»

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  • Overload Alleviation With Preventive-Corrective Static Security Using Fuzzy Logic

    Publication Year: 2009 , Page(s): 134 - 145
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (842 KB) |  | HTML iconHTML  

    This paper presents a concept overview of an automatic operator of electrical networks (AOEN) for real-time alleviation of component overloads and increase of system static loadability, based on state-estimator data only. The control used for this purpose is real-power generation rescheduling, although any other control input could fit the new framework. The key performance metrics are the vulnerability index of a generation unit (VIGS) and its sensitivity (SVIGS), accurately computed using a realistic ac power flow incorporating the AGC model (AGC-PF). Transmission overloads, vulnerability indices and their sensitivities with respect to generation control are translated into fuzzy-set notations to formulate, transparently, the relationships between incremental line flows and the active power output of each controllable generator. A fuzzy-rule-based system is formed to select the best controllers, their movement and step-size, so as to minimize the overall vulnerability of the generating system while eliminating overflows. The controller performance is illustrated on the IEEE 39-bus (New England) network and the three-area IEEE-RTS96 network subjected to severe line outage contingencies. A key result is that minimizing the proposed vulnerability metric in real-time results in increased substantial loadability (prevention) in addition to overload elimination (correction). View full abstract»

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  • Distributed Transient Stability Simulation of Power Systems Based on a Jacobian-Free Newton-GMRES Method

    Publication Year: 2009 , Page(s): 146 - 156
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1404 KB) |  | HTML iconHTML  

    As power systems becoming more closely interconnected and are being deregulated in energy markets, distributed simulations among different dispatch centers are highly required for online full system analysis and control applications. In this paper a new algorithm for distributed transient stability simulation of interconnected power systems is presented. Based on a Jacobian-free Newton-GMRES(m) method, this algorithm requires only exchanges of states of boundary buses among different regions. Therefore, it has strong scalability in distributed computing environments built on heterogeneous computing resources. Moreover, several accelerating methods are developed to enhance its efficiency, including continuous preconditioning with adaptive preconditioners, predicting boundary conditions and multistep coordination. The standard IEEE 39-bus system and a real power system with 1165 buses were used as test systems. The test results show that these accelerating methods greatly enhance the convergence rate of the proposed algorithm and reduce communication costs remarkably, which proves the novel algorithm is feasible and can be adopted in wide area networks with high-latency. View full abstract»

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  • Induction Machine Modeling Based on Shifted Frequency Analysis

    Publication Year: 2009 , Page(s): 157 - 164
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (363 KB) |  | HTML iconHTML  

    Electromagnetic transient program (EMTP) simulators are being widely used in power system dynamics studies. However, their capability in real-time simulation of power systems is compromised due to the small time step used and relatively slow simulation speed. The shifted frequency analysis (SFA) is then proposed to accelerate the EMTP simulations for power system dynamics. The objective of this paper is to extend the SFA method to model the induction machines in EMTP. By analyzing the relationship between rotor and stator physical variables, a phase-coordinate model with lower number of equations is first derived. Based on this, an SFA model is proposed as a general purpose model capable of simulating both fast transients and slow dynamics. Case study results have confirmed the SFA induction machine model is a valuable component for real-time EMTP simulations. It is observed that the SFA model is in excess of 70 times faster than the standard EMTP model when simulating dynamics with frequency spectra close to the fundamental power frequency. View full abstract»

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  • A Continuation-Based Method to Compute the Relevant Unstable Equilibrium Points for Power System Transient Stability Analysis

    Publication Year: 2009 , Page(s): 165 - 172
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB) |  | HTML iconHTML  

    The computation of the unstable equilibrium point (UEP) is a key step involved in the direct methods of power system transient stability analysis. A new continuation-based method to compute the UEPs is proposed. The mechanical powers of the generators are changed to form a parameterized equation. Then the solution curve of the equation is traced by the continuation method from the stable equilibrium point to a UEP. The direction of power increase is determined to get a UEP relevant to the fault. The obtained UEPs are mostly type-1 and the method is applicable to detailed generator models. The method is tested in several systems and satisfactory results are obtained. View full abstract»

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  • Frequency Regulation Contribution Through Variable-Speed Wind Energy Conversion Systems

    Publication Year: 2009 , Page(s): 173 - 180
    Cited by:  Papers (51)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (555 KB) |  | HTML iconHTML  

    This paper presents a new method to enhance the participation of variable-speed wind energy conversion systems (WECS) in existing frequency regulation mechanisms. The proposed approach, based on a modified inertial control scheme, takes advantage of the fast response capability associated with electronically-controlled WECS, allowing the kinetic energy stored by rotational masses to be partly and transiently released in order to provide earlier frequency support. An additional improvement is achieved by communicating the WECS response to conventional generators so that these can eventually take care of the full load imbalance. Several simulations using a two-area test system are performed to demonstrate the benefits of the proposed scheme. View full abstract»

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  • Response of Fixed Speed Wind Turbines to System Frequency Disturbances

    Publication Year: 2009 , Page(s): 181 - 192
    Cited by:  Papers (31)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (447 KB) |  | HTML iconHTML  

    This paper analyzes the impact of system frequency variations on the steady-state operation point of fixed speed induction generators used in wind turbine generation systems (WTGS). An analytic method to predict the values of angular speed, torque and current during and after a frequency disturbance is presented. The proposed method as well permits to establish the operation limits in order to keep the WTGS connected during frequency variations and therefore to adjust protection relay settings. View full abstract»

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  • Optimization Study on Voltage Level and Transmission Capacity

    Publication Year: 2009 , Page(s): 193 - 197
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (408 KB) |  | HTML iconHTML  

    Jinsha river has very abundant hydro power reservation, ranking first in all the hydro power bases of China. To deliver the 38-GW hydro power from Jinsha power stations by HVDC transmission lines to load centers 1000-2000 km away, it is necessary to determine the right voltage level and the capacity of each bipole. This paper proposes three preliminary power delivery scheme and presents an optimization method for transmission capacity, dc voltage and conductor size. Based on a comprehensive comparison of cost-effectiveness, technical feasibility and network security and stability, it was recommended that the 3 bipolar plusmn 800-kV ultra HVDC (UHVDC) links with rated capacity of 6.4 GW for each link be adopted as transmission scheme of phase I hydro power station on Jinsha River. View full abstract»

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  • Assessment and Enhancement of Small Signal Stability Considering Uncertainties

    Publication Year: 2009 , Page(s): 198 - 207
    Cited by:  Papers (25)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (609 KB) |  | HTML iconHTML  

    This paper proposes a probabilistic small signal stability assessment (PSSSA) methodology based on the application of Monte Carlo approach for iterative evaluation, via modal analysis of small signal stability (SSS). Operation states represented by random values of generation and demand are analyzed. A probabilistic instability risk index based on cumulative probability distribution function of damping ratios of oscillatory modes is calculated, as well as a power system stabilizer (PSS) devices location index based on eigenvectors and participation factors, which are considered random variables. Moreover, the impact of long-distance power flows on oscillatory modes (OM) and how the damping of OM depends on the orientation and magnitude of power flows is investigated. Further, an additional index concerns qualitatively the determination of transfer capability as affected by small signal stability. PSSSA is tested on a reduced order model of New England-New York's interconnected system considering uncertainties around three different system conditions separately: highly loaded, fairly loaded, and lowly loaded. The results highlight the main advantages of PSSSA over deterministic SSS studies such as instability risk assessment, small signal stability enhancement through adequate PSS location, and the proposal of possible restrictions for transfer capability in order to avoid poorly damped oscillations in the face of the diversity in power system operation. View full abstract»

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  • Wide-Area Measurements-Based Two-Level Control Design Considering Signal Transmission Delay

    Publication Year: 2009 , Page(s): 208 - 216
    Cited by:  Papers (48)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (647 KB) |  | HTML iconHTML  

    In this paper the design of power system stabilizers for small-signal stability using phasor measurements is considered. An approach based on optimal control with structural constraints is proposed to design a two-level control structure. Time delays are included in the design. The method is combined with order reduction to ensure faster convergence of the design algorithm and to facilitate the choice of the weighting matrices for damping interarea modes. The control scheme is discussed and modal analysis and time-domain simulations of two Brazilian equivalent systems are performed to assess the control performance. The robustness to loss of communication links, topological changes, and variations of time delay is evaluated. View full abstract»

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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