Topic
Power-flow study
About: Power-flow study is a research topic. Over the lifetime, 8091 publications have been published within this topic receiving 155053 citations. The topic is also known as: load-flow study.
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TL;DR: A power analysis technique is developed that has been applied to two commercial microprocessors and can be employed to evaluate the power cost of embedded software and can help in verifying if a design meets its specified power constraints.
Abstract: Embedded computer systems are characterized by the presence of a dedicated processor and the software that runs on it Power constraints are increasingly becoming the critical component of the design specification of these systems At present, however, power analysis tools can only be applied at the lower levels of the design-the circuit or gate level It is either impractical or impossible to use the lower level tools to estimate the power cost of the software component of the system This paper describes the first systematic attempt to model this power cost A power analysis technique is developed that has been applied to two commercial microprocessors-Intel 486DX2 and Fujitsu SPARClite 934 This technique can be employed to evaluate the power cost of embedded software This can help in verifying if a design meets its specified power constraints Further, it can also be used to search the design space in software power optimization Examples with power reduction of up to 40%, obtained by rewriting code using the information provided by the instruction level power model, illustrate the potential of this idea >
1,055 citations
TL;DR: In this paper, the authors re-examine linear MW-only ldquodcrdquo network power flow models and show that when their MW flows are reasonably correct, they can often offer compelling advantages.
Abstract: Linear MW-only ldquodcrdquo network power flow models are in widespread and even increasing use, particularly in congestion-constrained market applications. Many versions of these approximate models are possible. When their MW flows are reasonably correct (and this is by no means assured), they can often offer compelling advantages. Given their considerable importance in today's electric power industry, dc models merit closer scrutiny. This paper attempts such a re-examination.
937 citations
TL;DR: In this paper, the authors describe the development and evaluation of an analytical method for the direct determination of transient stability, which is based on the analysis of transient energy and accounts for the nature of the system disturbance as well as for the effects of transfer conductances on systenmbehavior.
Abstract: This paper describes the development and evaluation of an analytical method for the direct determination of transient stability. The method developed is based on the analysis of transient energy and accounts for the nature of the system disturbance as well as for the effects of transfer conductances onsystenmbehavior. It has been evaluated on a 10 generator 39 bus system and on a 20 generator 118 bus system. The method predicts critical clearing times for first swing transient stability which agree very closely with the results of simulations.
929 citations
TL;DR: In this paper, a generalized theory of instantaneous reactive power for three-phase power systems is proposed, which is valid for sinusoidal or nonsinusoidal, balanced or unbalanced, three phase power systems with or without zero-sequence currents and/or voltages.
Abstract: A generalized theory of instantaneous reactive power for three-phase power systems is proposed in this paper. This theory gives a generalized definition of instantaneous reactive power, which is valid for sinusoidal or nonsinusoidal, balanced or unbalanced, three-phase power systems with or without zero-sequence currents and/or voltages. The properties and physical meanings of the newly defined instantaneous reactive power are discussed in detail. A three-phase harmonic distorted power system with zero-sequence components is then used as an example to show reactive power measurement and compensation using the proposed theory.
755 citations
Book•
01 Jan 1986
TL;DR: In this article, the authors present a model of a single machine-infinite bus (SIB) with three-phase transformer connections for the purpose of detecting faults in a generator.
Abstract: 1. Background. Introduction. Electric Energy. Fossil-Fuel Plant. Nuclear Power Plant. Hydroelectric Power Plant. Other Energy Sources. Transmission and Distribution Systems. The Deregulated Electric Power Industry. 2. Basic Principles. Introduction. Phasor Representation. Complex Power Supplied to a One-Port. Conservation of Complex Power. Balanced Three-Phase. Per Phase Analysis. Balanced Three-Phase Power. Summary. 3. Transmission-Line Parameters. Introduction. Review of Magnetics. Flux Linkages of Infinite Straight Wire. Flux Linkages Many-Conductor Case. Conductor Bundling. Transposition. Impedance of Three Phase lines Including Ground Return. Review of Electric Fields. Line Capacitance. Determination of Line Parameters Using Tables. Typical Parameter Values. Summary. 4. Transmission-Line Modeling. Introduction. Derivation of Terminal V, I Relations. Waves on Transmission Lines. Transmission Matrix. Lumped-Circuit Equivalent. Simplified Models. Complex Power Transmission (Short Line). Complex Power Transmission (Radial Line). Complex Power Transmission (Long or Medium Lines). Power-Handling Capability of Lines. Summary. 5. Transformer Modeling and the Per Unit System. Introduction. Single-Phase Transformer Model. Three-Phase Transformer Connections. Per Phase Analysis. Normal Systems. Per Unit Normalization. Per Unit Three-Phase Quantities. Change of Base. Per Unit Analysis of Normal System. Regulating Transformers for Voltage and Phase Angle Control. Autotransformers. Transmission Line and Transformers. Summary 6. Generator Modeling I (Machine Viewpoint). Introduction. Classical Machine Description. Voltage Generation. Open-Circuit Voltage. Armature Reaction. Terminal Voltage. Power Delivered by Generator. Synchronizing Generator to an Infinite Bus. Synchronous Condensor. Role of Synchronous Machine Excitation in Controlling Reactive Power. Summary. 7. Generator Modeling II (Circuit Viewpoint). Introduction. Energy Conversion. Application to Synchronous Machine. The Park Transformation. Park's Voltage Equation. Park's Mechanical Equation. Circuit Model. Instantaneous Power Output. Applications. Synchronous Operation. Steady-State Model. Simplified Dynamic Model. Generator Connected to Infinite Bus (Linear Model). Summary 8. Generator Voltage Control. Introduction. Exciter System Block Diagram. Generator Models. Stability of Excitation System. Voltage Regulation. Generator Connected to Infinite Bus. Summary. 9. Network Matrices. Introduction. Bus Admittance Matrix. Network Solution. Network Reduction (Kron Reduction). YBUS Structure and Manipulation. Bus Impedance Matrix. Inverse Elements to Determine Columns of ZBUS. Summary. 10. Power Flow Analysis. Introduction. Power Flow Equations. The Power Flow Problem. Solution by Gauss Iteration. More General Iteration Scheme. Newton-Raphson Iteration. Application to Power Flow Equations. Decoupled Power Flow. Control Implications. Regulating Transformers in Power Flow Analysis, Power Flow Solutions for Large Power Systems. Summary. 11. Automatic Generation Control and the New Market Environment. Introduction. Power Control System Modeling. Application to Single Machine-Infinite Bus System. Simplified Analysis of Power Control System. Power Control, Multigenerator Case. Special Case Two Generating Units. Division of Power System Into Control Areas. Formulation of the Economic Dispatch Problem. Classical Economic Dispatch (Line Losses Neglected). Generator Limits Included. Line Losses Considered. Calculation of Penalty Factors. Economic Issues and Mechanisms in the New Market Environment. Transmission Issues and Effects in the New Market Environment. Summary. 12. Unbalanced System Operation. Introduction. Symmetrical Components. Use of Symmetrical Components for Fault Analysis. Sequence Network Connections for Different Types of Faults. More General Fault Circuit Analysis. Power From Sequence Variables. Sequence Representation of Y and ...D Connected Circuits. Generator Models for Sequence Networks. Transformer Models for Sequence Networks. Sequence Representation of Transmission Lines. Assembly of Sequence Networks. Fault Analysis for Realistic Power System Model. Matrix Methods. Summary. 13. System Protection. Introduction. Protection of Radial Systems. System with Two Sources. Impedance (Distance) Relays. Modified-Impedance Relays. Differential Protection of Generators. Differential Protection of Transformers. Differential Protection of Buses and Lines. Overlapping Zones of Protection. Sequence Filters. Computer Relaying. Summary. 14. Power System Stability. Introduction. Model. Energy Balance. Linearization of Swing Equation. Solution of Nonlinear Swing Equation. Other Applications. Extension to Two-Machine Case. Multimachine Application. Multimachine Stability Studies. Summary. Appendices. Reluctance. Force Generation in a Solenoid. Method of Lagrange Multipliers. Root-Locus Method. Negative- and Zero-Sequence Impedances of Synchronous Machines. Inversion Formula. Modification of Impedance Matrices. Conductor Characteristics. Selected Bibliography. Index.
749 citations