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Showing papers on "Power system simulation published in 2003"


Journal ArticleDOI
TL;DR: In this article, a mixed-integer LP approach to the solution of the long-term transmission expansion planning problem is presented. But this approach is not suitable for large-scale systems, as the problem is large scale, mixed integer, nonlinear, and nonconvex.
Abstract: This paper presents a mixed-integer LP approach to the solution of the long-term transmission expansion planning problem. In general, this problem is large-scale, mixed-integer, nonlinear, and nonconvex. We derive a mixed-integer linear formulation that considers losses and guarantees convergence to optimality using existing optimization software. The proposed model is applied to Garver's 6-bus system, the IEEE Reliability Test System, and a realistic Brazilian system. Simulation results show the accuracy as well as the efficiency of the proposed solution technique.

454 citations


Journal ArticleDOI
TL;DR: In this article, the authors focus on fundamental frequency simulations, also known as electromechanical transient simulations, where the network is represented as an impedance matrix and only the fundamental frequency component of voltages and currents is taken into account in order to reduce the computation time.
Abstract: Increasing numbers of wind turbines are being erected. In the near future, they may start to influence the dynamics of electrical power systems by interacting with conventional generation equipment and with loads. The impact of wind turbines on the dynamics of electrical power systems therefore becomes an important subject, studied by means of power system dynamics simulations. Various types of power system dynamics simulations exist and the approach depends on the aspect of power system dynamic behavior being investigated. In this paper, the focus is on fundamental frequency simulations, also known as electromechanical transient simulations. In this type of simulation, the network is represented as an impedance matrix and only the fundamental frequency component of voltages and currents is taken into account in order to reduce the computation time. This simulation approach is mainly used for voltage and angle stability investigations. Models of wind turbine generating systems that match the fundamental frequency simulation approach are presented and their responses are compared to measurements.

340 citations


Journal ArticleDOI
TL;DR: In this article, the authors mainly studied how to find proper splitting strategies of large-scale power systems using an ordered binary decision diagrams (OBDD)-based three-phase method and a time-based layered structure of the problem solving process was introduced to make this method more practical.
Abstract: System splitting problem (SS problem) is to determine proper splitting points (or called splitting strategies) to split the entire interconnected transmission network into islands ensuring generation/load balance and satisfaction of transmission capacity constraints when islanding operation of a system is unavoidable. For a large-scale power system, its SS problem is very complicated in general because a combinatorial explosion of strategy space happens. This paper mainly studies how to find proper splitting strategies of large-scale power systems using an ordered binary decision diagrams (OBDD)-based three-phase method. Then, a time-based layered structure of the problem solving process is introduced to make this method more practical. Simulation results on IEEE 30- and 118-bus networks show that by this method, proper splitting strategies can be given quickly. Further analyses indicate that this method is effective for larger-scale power systems.

296 citations


Proceedings ArticleDOI
23 Jun 2003
TL;DR: This paper addresses online estimation of electromechanical oscillatory modes in power systems using dynamic data such as currents, voltages and angle differences measured on-line across transmission lines using newly installed phasor measurement units (PMUs).
Abstract: This paper addresses online estimation of electromechanical oscillatory modes in power systems using dynamic data such as currents, voltages and angle differences measured on-line across transmission lines. These measurements are provided by newly installed phasor measurement units (PMUs). Here, the collected data are evaluated with the main objective to detect the dominant frequency and damping of oscillations during normal operation of the power system. The goal is to give the transmission operator qualitative and quantitative information about actual oscillations in the power system as well as about related properties, such as stability margins. The approach is demonstrated on a model of a real power system. Several problems and limitations of the approach are pointed out as well.

158 citations


Journal ArticleDOI
TL;DR: In this paper, a dynamic programming (DP) optimization model is proposed for real-time optimal unit scheduling in satisfying complex operational constraints while improving basin-wide generation efficiency, subject to plant constraints on total generation requirements, generation shape requirements, and spinning reserve; and operational restrictions on rough zone avoidance, minimum up and down time requirements and unit outage modes.
Abstract: The hydropower unit commitment and loading problem represents a complex decision-making process involving the integrated hourly scheduling of generators in a multiproject hydropower system. Optimal scheduling maximizes basinwide operating efficiency while satisfying power load demands, water demands, reliability constraints, operational restrictions, and security requirements. Often considered as a sequentially static optimization over each operational period, the problem actually embodies a highly dynamic structure when considering realistic operational restrictions on unit commitment and loading. A dynamic programming (DP) optimization model maximizes basinwide operating efficiency subject to (1) plant constraints on total generation requirements, generation shape requirements, and spinning reserve; and (2) operational restrictions on rough zone avoidance, minimum up and down time requirements, and unit outage modes. Application of the DP model to the hydropower system of the Lower Colorado River Basin demonstrates its capabilities for real-time optimal unit scheduling in satisfying complex operational constraints while improving basinwide generation efficiency.

103 citations


Proceedings ArticleDOI
14 Dec 2003
TL;DR: The results reported in this paper demonstrate the effectiveness of the particle swarm optimizer in the tuning of the AGC parameters and the enhancement in the dynamic response of the power system is verified through simulation results.
Abstract: This paper demonstrates the use of particle swarm optimization for optimizing the parameters of automatic generation control systems (AGC) An integral controller and a proportional-plus-integral controller are considered A two-area reheat thermal system is considered to exemplify the optimum parameter search The optimal AGC parameters search is formulated as an optimization problem with a standard infinite time quadratic objective function A time domain simulation of the system is then used in conjunction with the particle swarm optimizer to determine the controller gains The integral square of the error and the integral of time-multiplied absolute value of the error performances indices are considered The results reported in this paper demonstrate the effectiveness of the particle swarm optimizer in the tuning of the AGC parameters The enhancement in the dynamic response of the power system is verified through simulation results

94 citations


Proceedings ArticleDOI
13 Jul 2003
TL;DR: In this paper, a load flow and stability model for wind energy conversion systems was developed for a commercial power system load flow, and all significant air-dynamical, mechanical, and electrical factors have been reviewed and modeled appropriately.
Abstract: Wind energy conversion systems comprise mechanical and electrical equipment and their controls. Modeling these systems for power system stability simulation studies requires careful analysis of the equipment and controls to determine the characteristics that are important in the timeframe and bandwidth of such studies. Just as important, the characteristics must be reviewed to put aside factors that can be important for wind turbine/wind farm design but do not play a decisive role for the wind turbine/wind farm response from a system standpoint or whose characteristics are not relevant to the frequency range typical for power system stability performance. With this in mind, models of wind turbine units and wind farms are being developed for a commercial power system load flow and stability simulation package. All significant air-dynamical, mechanical, and electrical factors have been reviewed and are modeled appropriately. Load flow models allow aggregation of wind farms comprising tens to hundreds of wind turbine units and easy addition of an equivalent of the wind farm to the model of the existing system. Dynamic models represent different types of constant speed and variable speed technologies currently employed by manufacturers, with their controls.

91 citations


Journal ArticleDOI
John Olav Giæver Tande1
TL;DR: In this paper, the impact of wind turbines on voltage quality and power system stability in distribution grids is discussed. But the authors focus on the impact on slow voltage variations, flicker, voltage dips and harmonics.
Abstract: This article gives an overview of grid integration of wind farms with respect to impact on voltage quality and power system stability. The recommended procedure for assessing the impact of wind turbines on voltage quality in distribution grids is presented. The procedure uses the power quality characteristic data of wind turbines to determine the impact on slow voltage variations, flicker, voltage dips and harmonics. The detailed assessment allows for substantially more wind power in distribution grids compared with previously used rule-of-thumb guidelines. Power system stability is a concern in conjunction with large wind farms or very weak grids. Assessment requires the use of power system simulation tools, and wind farm models for inclusion in such tools are presently being developed. A fixed-speed wind turbine model is described. The model may be considered a good starting point for development of more advanced models, hereunder the concept of variable-speed wind turbines with a doubly fed induction generator is briefly explained. The use of dynamic wind farm models as part of power system simulation tools allows for detailed studies and development of innovative grid integration techniques. It is demonstrated that the use of reactive compensation may relax the short-term voltage stability limit and allow integration of significantly more wind power, and that application of automatic generation control technology may be an efficient means to circumvent thermal transmission capacity constraints. The continuous development of analysis tools and technology for cost-effective and secure grid integration is an important aid to ensure the increasing use of wind energy. A key factor for success, however, is the communication of results and gained experience, and in this regard it is hoped that this article may contribute. Copyright © 2003 John Wiley & Sons, Ltd.

69 citations


Proceedings ArticleDOI
13 Jul 2003
TL;DR: In this paper, a general approach to real-time transient stability control is proposed, and two complementary techniques are devised: one for preventive, the other for emergency control, which consists of shifting active power generation.
Abstract: Summary form only given. A general approach to real-time transient stability control is proposed, and two complementary techniques are devised: one for preventive, the other for emergency control. In this paper, the general transient stability control approach is first revisited then applied to real-time preventive control. The technique consists of shifting active power generation. The amount of power and the machines from which to shift it are methodically determined, and various patterns of generation decrease/increase are considered. Further, a standard OPF algorithm is combined with this control technique to get a real-time transient stability-constrained OPF software, able to meet power system security and electricity market requirements. Simulations conducted on the 88-machine EPRI system and the Mexican interconnected power system, illustrate the various techniques, highlight their specifics and assess their performance.

68 citations


Proceedings ArticleDOI
15 Jun 2003
TL;DR: In this paper, the observed phenomena of harmonic interference of large populations of these inverters and compare the network interaction of different inverter topologies and control options are investigated using extensive laboratory experiments.
Abstract: Power quality problems associated with distributed power inverters, implemented in high numbers in the same distribution network, are investigated. These power quality problems are currently mainly found in projects with large penetration of photovoltaics on roof-tops of houses and commercial buildings. The main object of this paper is to analyse the observed phenomena of harmonic interference of large populations of these inverters and compare the network interaction of different inverter topologies and control options. These power quality phenomenon are investigated using extensive laboratory experiments on inverter topologies, as well as computer modelling of different inverter topologies. A complete network simulation study on a real residential network with large penetration of PV is included.

66 citations


Journal ArticleDOI
TL;DR: In this paper, a unified exposition of various definitions of reactive power and of various compensation methods is provided, and a comparative Hilbert space analysis of definitions used in power system studies and in electric drives (the so called instantaneous reactive power).
Abstract: The paper provides a unified exposition of various definitions of reactive (or inactive) power and of various compensation methods. In particular, it presents a comparative Hilbert space analysis of definitions used in power system studies and in electric drives (the so called instantaneous reactive power). The paper casts several compensation strategies (such as compensation without energy storage and compensation with linear shunt components) in a common framework, and utilizes the concept of orthogonal projections on suitable subspaces as the main analytical and computational tool. Various notions are illustrated on two examples.

Proceedings ArticleDOI
Hopkinson1, Birman1, Giovanini, Coury, Wang, Thorp 
07 Dec 2003
TL;DR: The development of the Electric Power and Communication Synchronizing Simulator (EPOCHS), a distributed simulation environment that allows users to transparently encapsulate complex system behavior that bridges multiple domains through the use of a simple agent-based framework.
Abstract: We report on the development of the Electric Power and Communication Synchronizing Simulator (EPOCHS), a distributed simulation environment. Existing electric power simulation tools accurately model power systems of the past, which were controlled as large regional power pools without significant communication elements. However, as power systems increasingly turn to protection and control systems that make use of computer networks, these simulators are less and less capable of predicting the likely behavior of the resulting power grids. Similarly, the tools used to evaluate new communication protocols and systems have been developed without attention to the roles they might play in power scenarios. EPOCHS utilizes multiple research and commercial off-the-shelf (COTS) systems to bridge the gap. EPOCHS is also notable for allowing users to transparently encapsulate complex system behavior that bridges multiple domains through the use of a simple agent-based framework.

Journal ArticleDOI
TL;DR: An investigation of a methodology using intelligent learning techniques based on system measurements to construct power system load models alongside with distribution network reduction and a population diversity-based genetic algorithm is developed to obtain the structure and parameters of the load model.
Abstract: This paper is concerned with an investigation of a methodology using intelligent learning techniques based on system measurements to construct power system load models alongside with distribution network reduction. A comprehensive load model is proposed to represent the loads in an area of a power system. A population diversity-based genetic algorithm (GA) is developed to obtain the structure and parameters of the load model. Simulation results on a five-bus power system and an IEEE 30-bus power system are given to show the potential of this new methodology of power system modeling.

Proceedings ArticleDOI
16 Mar 2003
TL;DR: In this paper, a split-shaft micro-turbine model using induction generators is used to assist transient stability of microturbines when connected to the grid as distributed generator.
Abstract: In this paper, a split-shaft microturbine model using induction generators is used to assist transient stability of microturbines when connected to the grid as distributed generator Microturbines can be controlled via two paths, control of the turbine's mechanical power and control of terminal voltage from induction generator using connected SVC at the generator's terminal PI controllers, for SVC and output turbine mechanical power, are designed based on a linearized model using genetic algorithms as optimization technique Model development and simulation are presented within the MATLAB/Simulink (Power System Analysis Toolbox (PAT)) environment using various toolboxes

Journal ArticleDOI
13 May 2003
TL;DR: In this paper, a doubly-fed induction generator (DFIG) wind turbine in large power system dynamic simulation software is discussed, and a direct solution method for obtaining injected rotor voltages, which satisfy the dynamic model control objectives, is derived from the approximate steady state model.
Abstract: The modelling of a doubly-fed induction generator (DFIG) wind turbine in large power system dynamic simulation software is discussed, and the steady state equivalent circuit and reduced order dynamic DFIG models are described. A direct solution method for obtaining injected rotor voltages, which satisfy the dynamic model control objectives, is derived from the approximate steady state model. An initialisation procedure is given for the reduced order dynamic DFIG machine model. Simulation results are presented from initialised dynamic DFIG wind turbine models. PQ and PV bus representations of the DFIG for load flow studies are compared and simulated with typical turbine and network data for wind farm installations.

Journal ArticleDOI
TL;DR: In this article, a scheduling method for representing the thermal stress of turbine shafts as ramp rate constraints in the thermal commitment and dispatch of generating units is presented, which is based on Lagrangian relaxation for optimal generation scheduling.
Abstract: This paper describes a scheduling method for representing the thermal stress of turbine shafts as ramp rate constraints in the thermal commitment and dispatch of generating units. The paper uses Lagrangian relaxation for optimal generation scheduling. In applying the unit commitment, thermal stress over the elastic limit is used for calculating the ramping cost. The thermal stress contribution to generation cost requires the calculation of a set that includes thermal stress at the end of each time step; this requirement presents a complicated problem which cannot be solved by an ordinary optimization method such as dynamic programming. The paper uses an improved simulated annealing method to determine the optimal trajectory of each generating unit. Furthermore, the paper uses linear programming for economic dispatch in which thermal stress limits are incorporated in place of fixed ramp rate limits. The paper illustrates the economics of frequently ramping up/down of low cost generating units versus the cost of replacement of their turbine rotors with a shorter life span. The experimental results for a practical system demonstrate the effectiveness of the proposed method in optimizing the power system generation scheduling.

Proceedings ArticleDOI
K. Uhlen1, S. Elenius, I. Norheim, J. Jyrinsalo, J. Elovaara, E. Lakervi 
13 Jul 2003
TL;DR: In this paper, the authors present research work on stability assessment and stabilizer design that has been carried out for the Finnish transmission system operator, Fingrid. The aim of the work has been to assess observability and controllability of low frequency inter-area modes and to design stabilizing controls to improve damping of critical modes.
Abstract: This paper presents research work on stability assessment and stabilizer design that has been carried out for the Finnish transmission system operator, Fingrid. The aim of the work has been to assess observability and controllability of low frequency inter-area modes in the Finnish transmission grid, and to design stabilizing controls to improve damping of critical modes. Challenges in system modeling are described, and main results from linear analyses are presented and compared with nonlinear dynamic simulations. The results are seen to correspond well with real system observations. Modal analysis and nonlinear simulations are applied to verify design of power system stabilizers of some important generators in Finland. Similar methods are also used for retuning and verification of stabilizers on the Fennoskan HVDC link between Sweden and Finland. The stabilizer performance is demonstrated in terms of stability improvements. A main conclusion is that linear techniques can be of great benefit when designing damping controllers for large power systems. It is also illustrated, with the use of validated models, how linear tools can be used in operation planning for determination of power transfer limits.

Journal ArticleDOI
TL;DR: A formulation for the commitment of electric power generators under a deregulated electricity market is proposed, expressed as a stochastic optimization problem in which expected profits are maximized while meeting demand and standard operating constraints.
Abstract: A formulation for the commitment of electric power generators under a deregulated electricity market is proposed. The problem is expressed as a stochastic optimization problem in which expected profits are maximized while meeting demand and standard operating constraints. Under an assumption of perfect competition, when an electric power producer has the option of trading electricity at market prices, a unit commitment schedule can be obtained by optimizing the self-commitment of each unit separately subject to stochastic prices. Three certainty-equivalent formulations of the stochastic self-commitment problem are provided. The procedures involve application of dynamic programming, statistical analysis, and asymptotic probability computations. The price of electricity is represented by a stochastic model depending on demand, generating unit reliabilities, and temperature fluctuations. We use several approximation methods (normal, Edgeworth series expansion, and Monte Carlo simulation) for computing the required probability distributions. Numerical examples are provided for a market consisting of 150 generating units.

Proceedings ArticleDOI
13 Jul 2003
TL;DR: In this article, the authors present simulation results calculated using a representative network containing wind power generation of up to 30% for a doubly-fed induction machine, whose primary control structure comprises of decoupled active and reactive power control channels.
Abstract: With the increased use of wind power, particularly in wind-farms, the voltage and frequency behaviors of the whole network are likely to be affected significantly. This paper presents simulation results calculated using a representative network containing wind power generations of up to 30%. Furthermore, modelling and simulation of different types of wind generators integrated into a multimachine power system are discussed. Special interest is focused on the doubly-fed induction machine, whose primary control structure comprises of decoupled active and reactive power control channels. The overall control scheme also includes power, speed and voltage control loops, which provide the reference values for active and reactive power. It is shown that with a simple extension of the control structure, wind generators can participate on the network frequency control and thus are able to reduce the adverse effects of the wind farms on the overall performance of the network.

Proceedings ArticleDOI
23 Jun 2003
TL;DR: In this paper, the influence of large offshore wind farms on the performance of the system to which they are connected is explored and the response of the wind farm to a major load change in a large multi-machine network is simulated and the results discussed.
Abstract: The paper explores the influence of large offshore wind farms on the performance of the system to which they are connected. To meet the emerging requirements of the power system with regard to voltage and frequency, controllers with extended features have been used that enable the control of the terminal voltage and the participation of large wind farms on system frequency control. The models of the wind turbine and the electrical machines together with the proposed control structure are integrated into a power system simulation environment Then, the impact of planned offshore wind farms on the transient stability performance of parallel operating conventional power plants and the bus voltage profile of the network during fault for alternative wind generator types are investigated. Additionally, the response of the wind farm to a major load change in a large multi-machine network is simulated and the results discussed.

Proceedings ArticleDOI
13 Jul 2003
TL;DR: Results obtained show improvement in the overall system damping characteristics using the proposed adaptive fuzzy PSS (AFPSS), which is based on the steepest descent algorithm.
Abstract: An adaptive power system stabilizer consisting of an online identified planet model and self-learning fuzzy logic controller, for power system stabilizer (PSS) application is described in this paper. On-line model identification is used to obtain a dynamic equivalent model for the synchronous machine with respect to the rest of the system. A fuzzy controller with self-learning capability is then used to adapt the system performance. The self-learning ability of the fuzzy controller is based on the steepest descent algorithm. The effectiveness of the proposed technique is demonstrated on a power system by simulation studies. Results obtained show improvement in the overall system damping characteristics using the proposed adaptive fuzzy PSS (AFPSS).

Proceedings ArticleDOI
07 May 2003
TL;DR: In this article, a load frequency controller based on model predictive control (MPC) is proposed to minimize unit maneuvering and reversals, which affect load frequency control (LFC) costs.
Abstract: In this paper, model predictive control (MPC) scheme is used to develop the proposed load frequency controller. In each sampling interval, an optimization procedure is performed to calculate optimal control actions. In addition, it has the ability to incorporate economic objectives as part of control requirements. Here, it applies the wedge control philosophy to minimize unit maneuvering and reversals, which affect load frequency control (LFC) costs. The proposed methodology is tested with a three-area power system. Simulation results show that the proposed LFC successfully complies with NERC's control performance standards, and also achieves the economic objective.

Proceedings ArticleDOI
01 Jan 2003
TL;DR: In this paper, a stochastic source is coupled over a DC bus with diverse storage modules and a grid interface, and a second form of storage for quasi-instantaneous power delivery is considered, where the intermittent source is transformed into an emission-free deterministic generation plant with controlled power output to the grid.
Abstract: The market for distributed energy resources expands rapidly Two distributed energy sources that are at the center of interest in this context are wind energy converters and fuel cells While renewable energy based and environmentally benign, a major problem of wind energy conversion with regard to large-scale network integration is the direct dependence of the power generation capability on the given wind speed Similar problems of controllability exist for other renewable energy sources with intermittent output This conflicts with the need to schedule power output in a deterministic manner A concept to overcome the stochastic nature of the source is proposed The overall solution consists of a plant where the stochastic source is coupled over a DC bus with diverse storage modules and a versatile grid interface As storage solutions hydrogen and in addition a second form of storage for quasiinstantaneous power delivery is considered The intermittent source is so transformed into an emission-free deterministic generation plant with controlled power output to the grid

Proceedings ArticleDOI
19 Feb 2003
TL;DR: In this paper, two methods are presented to eliminate the numerical oscillations encountered in power system dynamic simulation resulting from trapezoidal numerical integration rule: trapezoid with numerical stabilizer method and Gear's second order method.
Abstract: This paper addresses numerical oscillations encountered in power system dynamic simulation resulting from trapezoidal numerical integration rule. Two methods are presented to eliminate the numerical oscillations: trapezoidal with numerical stabilizer method and Gear's second order method. A detailed comparison is given regarding the accuracy of the trapezoidal rule, trapezoidal with numerical stabilizer method, and Gear's method. The validity of the new methods is demonstrated in the simulation of a power electronic circuit within Virtual Test Bed. The new methods are of great significance in performing a meaningful simulation for power electronics circuits.

Proceedings ArticleDOI
13 Jul 2003
TL;DR: In this article, a simple technique for measurement placement method of power system state estimation is proposed, where the minimum condition number of the measurement matrix is used as the criteria in conjunction with sequential elimination to generalize the measurement placement.
Abstract: This paper deals with a simple technique for measurement placement method of power system state estimation The minimum condition number of the measurement matrix is used as the criteria in conjunction with sequential elimination to generalize the measurement placement The singular value decomposition (SVD) approach will be used to solve the state estimation The simulation study is performed on the IEEE 14-bus test system by linear weighted least square (WLS) It is found that, this algorithm can give a solution of measurement placement of injection current and voltage that make the power system observable

Proceedings ArticleDOI
13 Jul 2003
TL;DR: A Monte Carlo based power flow algorithm that integrates the deterministic and the stochastic natures of the new structured, electrical distributed generation systems is proposed and the results obtained are presented and discussed.
Abstract: A Monte Carlo based power flow algorithm that integrates the deterministic and the stochastic natures of the new structured, electrical distributed generation systems is proposed. The uncertainties in both the locations and the states (on or off) of the distributed generation (DG) units constitute the random parameters of the studied systems. A novel algorithm to incorporate these parameters into the Newton-Raphson solution of the power flow equations is carefully designed and implemented in this paper. Monte Carlo simulation is employed to perform the analysis of all the possible operation scenarios of the system under study and thus ensure the validity of the results. The proposed algorithm is employed to obtain the power flow solution for a typical distributed generation system involving several DG units and the results obtained are presented and discussed.

Proceedings ArticleDOI
Bei Xu1, Ali Abur1
23 Jun 2003
TL;DR: In this paper, the state estimation of flexible ac transmission systems (FACTS) is considered and a state estimation program is developed to determine the required settings for the controller parameters for a given operating condition.
Abstract: This paper is concerned about the state estimation of systems, which contain flexible ac transmission systems (FACTS) devices. State estimation formulation is modified in order to incorporate the detailed models of the unified power flow controllers (UPFC). This necessitates the use of equality and inequality constraints that account for the limits associated with the device operation and ratings. Furthermore, in addition to its use as an estimator, the developed program can also be used to determine the required settings for the controller parameters for a given operating condition. Simulations on small and medium sized power systems are presented to demonstrate the use of the developed program both as a state estimator and for setting the parameters of power flow controllers.

Proceedings ArticleDOI
23 Jun 2003
TL;DR: In this paper, the authors deal with the simultaneous coordinated tuning of the FACTS (flexible AC transmission systems) POD power oscillation damping controller and the conventional PSS (power system stabilizer) controllers in multimachine power systems.
Abstract: This work deals with the simultaneous coordinated tuning of the FACTS (flexible AC transmission systems) POD power oscillation damping) controller and the conventional PSS (power system stabilizer) controllers in multimachine power systems. Using the linearized system model and the parameter-constrained nonlinear optimization algorithm, interactions among FACTS controller and PSS controllers are considered. Furthermore, their parameters are optimized simultaneously. Simulation results of multimachine power system validate the efficiency of this new approach. The proposed algorithm is an effective method for the tuning of multicontrollers in large power systems.

Proceedings ArticleDOI
W. Xu1
13 Jul 2003
TL;DR: In this paper, the main developments and conclusions in the area of power system harmonic analysis have been summarized, with the help of four example research topics, and the possible future directions of power systems harmonic analysis research.
Abstract: This paper provides a concise review on the main developments and conclusions in the area of power system harmonic analysis. Commonly accepted methods for conducting harmonic studies have been summarized. The area of harmonic analysis is still a very fertile ground for exploration. With the help of four example research topics, the paper also demonstrates possible future directions of power system harmonic analysis research.

Journal ArticleDOI
TL;DR: In this article, a modal analysis of the power distribution system is presented and a series active filter controller is designed based on the reduced-order model to cancel the dominant LC resonances in the system.
Abstract: Expansion of voltage distortions along power distribution systems, which is referred to as the harmonic propagation, is pointed out. This is caused by the LC resonances between the distribution line inductances and the power capacitors. This paper presents a modeling and harmonic suppression procedure for power distribution systems. In our proposal, the power distribution system is analyzed based on the modal analysis and it is represented by a reduced-order model. For the harmonic suppression, a series active filter is used and its controller is designed based on the reduced-order model so as to cancel the dominant LC resonances in the power distribution system. Some significant characteristics are verified by experiments using a single-phase power distribution system.