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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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Proceedings ArticleDOI
01 Jun 1999
TL;DR: In this article, a principal-orthogonal decomposition based method is applied to the model reduction of a hybrid, nonlinear model of a power network, and the results demonstrate that the sequence of fault events can be evaluated and predicted without necessarily simulating the whole system.
Abstract: In this paper, we apply a principal-orthogonal decomposition based method to the model reduction of a hybrid, nonlinear model of a power network. The results demonstrate that the sequence of fault events can be evaluated and predicted without necessarily simulating the whole system.

69 citations

Proceedings ArticleDOI
03 Jan 2005
TL;DR: A novel power estimation framework is developed, based on a network of power monitors, that addresses a complementary problem - the optimized integration and usage of heterogeneous component power models within a system-level simulation framework.
Abstract: Power analysis early in the design cycle is critical for the design of low power systems. With the move to system-level specifications and design methodologies, there has been significant research interest in system-level power estimation. However, as demonstrated in this paper, the addition of power estimation capabilities to system-level simulation tools can significantly degrade simulation efficiency (up to 8.5/spl times/), limiting the use of power estimation during long simulation rum, and the ability to perform extensive design space exploration. Some power modeling techniques for system components provide "local" tradeoffs between power estimation accuracy and computational cost This work addresses a complementary problem - the optimized integration and usage of heterogeneous component power models within a system-level simulation framework. We view system-level power estimation as a global deployment of computational effort (the effort required to perform power estimation) over space (the different components) and time (the duration of the simulation). We illustrate the advantages of optimizing the allocation of power estimation effort based on run-time variations of component-level, as well as system-level power consumption characteristics. To achieve this, we have developed a novel power estimation framework, based on a network of power monitors. Power monitors observe component- and system-level execution and power statistics at run time, based on which they (I) select between multiple alternative power models for each component, and/or (II) configure the component power models, to best negotiate the trade-off between efficiency and accuracy. In effect, the power monitor network performs a coordinated, adaptive, spatio-temporal allocation of computational effort for power estimation. Experiments conducted on a commercial system-level simulation framework and system-on-chip platform demonstrate that the proposed techniques yield large reductions in power estimation overhead (nearly an order of magnitude), while minimally impacting power estimation accuracy.

69 citations

Journal ArticleDOI
TL;DR: In this article, the authors report on some recent results in the mathematics of stochastic processes which suggest a mechanism leading to small disturbance instabilities of this type in power systems, and the assumptions necessary to structure the model to produce this behavior are simple, flexible and consistent with possible operating conditions in an electrical power system.
Abstract: Unstable, oscillatory behavior has been observed on several occasions in electrical power systems operated in an unfaulted, normal state under moderate load. In some cases system failure has resulted from this behavior. In this paper, we report on some recent results in the mathematics of stochastic processes which suggest a mechanism leading to small disturbance instabilities of this type in power systems. Unstable oscillations in power angles may be produced in a system consisting of a synchronous machine with negligible damping weakly coupled through randomly fluctuating links to other machines each with positive damping. The assumptions necessary to structure the model to produce this behavior are simple, flexible and consistent with possible operating conditions in an electrical power system.

69 citations

Journal ArticleDOI
TL;DR: A mathematical programming-based approach to optimize the unit commitment problem with alternating current optimal power flow (ACOPF) network constraints, which can be extended to solve larger scale power systems as well as include security constraints or uncertainty through decomposition techniques.
Abstract: We propose a mathematical programming-based approach to optimize the unit commitment problem with alternating current optimal power flow (ACOPF) network constraints. This problem is a nonconvex mixed-integer nonlinear program (MINLP) that we solve through a solution technique based on the outer approximation method. Our solution technique cooptimizes real and reactive power scheduling and dispatch subject to both unit commitment constraints and ACOPF constraints. The proposed approach is a local solution method that leverages powerful linear and mixed-integer commercial solvers. We demonstrate the relative economic and operational impact of more accurate ACOPF constraint modeling on the unit commitment problem, when compared with copperplate and DCOPF constraint modeling approaches; we use a six-bus, the IEEE RTS-79, and the IEEE-118 test systems for this analysis. Our approach can be extended to solve larger scale power systems as well as include security constraints or uncertainty through decomposition techniques.

69 citations

Journal ArticleDOI
TL;DR: In this article, a new continuation power flow method tracing QV constraint exchange points (CEP) at which generators regulating voltages hit the reactive power limits is proposed, which is based on a predictor/corrector scheme to obtain CEPs in succession.
Abstract: This work proposes a new continuation power flow method tracing QV constraint exchange points (CEP), at which generators regulating voltages hit the reactive power limits. The proposed method is based on a predictor/corrector scheme to obtain CEPs in succession. The condition for Q-limit immediate instability is derived and used in the algorithm, where the stability of the obtained CEP is checked in each iteration. The point of collapse method is also combined in the algorithm to detect a saddle node bifurcation. The effectiveness of the proposed method is demonstrated through numerical examinations in IEEE 118 bus systems.

68 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202325
202283
2021162
2020179
2019228
2018221