Spelling suggestions: "subject:"power system stability"" "subject:"lower system stability""
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Power System Coherency Identification Using Nonlinear Koopman Mode AnalysisTbaileh, Ahmad Anan 01 July 2014 (has links)
In this thesis, we apply nonlinear Koopman mode analysis to decompose the swing dynamics of a power system into modes of oscillation, which are identified by analyzing the Koopman operator, a linear infinite-dimensional operator that may be defined for any nonlinear dynamical system. Specifically, power system modes of oscillation are identified through spectral analysis of the Koopman operator associated with a particular observable. This means that they can be determined directly from measurements. These modes, referred to as Koopman modes, are single-frequency oscillations, which may be extracted from nonlinear swing dynamics under small and large disturbances. They have an associated temporal frequency and growth rate. Consequently, they may be viewed as a nonlinear generalization of eigen-modes of a linearized system. Koopman mode analysis has been also applied to identify coherent swings and coherent groups of machines of a power system. This will allow us to carry out a model reduction of a large-scale system and to derive a precursor to monitor the loss of transient stability. / Master of Science
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Adaptive power system controlManansala, Edgardo Celestino January 1989 (has links)
This work presents a centralized control scheme applied to a power system. The scheme has adaptive characteristics which allow the controller to keep track of the changing power system operating point and to control nonlinear functions of state variables. Feedback to the controller is obtained from phasor measurements at chosen power system buses, generator field voltage measurements, and state estimators. Control effort is aimed at minimizing the oscillations and influencing the power system state trajectory through the control of linear and nonlinear functions of state variables during a power system disturbance.
The main contributions of this dissertation are the simultaneous introduction and utilization of measurement based terms in the state and output equations in the derivation and implementation of the control law, the study of limits on controller performance as the state residual vector becomes very large, and the simulation of the performance of local state estimators to prove the need for faster phasor measurement systems.
The test system is a hypothetical 39-Bus AC power system consisting of typical components which have been sufficiently modelled for the simulation of power system performance in a dynamic stability study. / Ph. D.
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Investigation of data reporting techniques & analysis of continuous power quality data in the Vector distribution networkNicholson, Glenn C. January 1900 (has links)
Thesis (M.Eng.)--University of Wollongong, School of Electrical, Computer & Telecommunications Engineering. / Typescript. Includes bibliographical references: leaf 143-147.
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A Novel Fuzzy Logic Based Controller For Power System Stabilizers And FACTS DevicesMajumder, Ritwik 07 1900 (has links) (PDF)
No description available.
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Transformerless series dip/sag compensation with ultracapacitorsBecker, Martin Gerhard 12 1900 (has links)
Thesis (MScIng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: This thesis covers the development of a transformerless series dip compensator. Of all known power
quality problems, voltage dips are the greatest reason for concern. Series injection dip compensators
offer the advantage of only having to compensate for the decrease in supply voltage during a dip.
This results in significant reduction in converter ratings and energy storage requirements. The aim of
this thesis was to take up previous developments and combine them with new technologies to
maximize their functionality. The new design was implemented with ultracapacitors to offer a
maintenance-free device lifespan of 20 years. As they are very expensive, a new topology was
introduced in this thesis to maximize their use so that they become viable for industry. Furthermore,
a new method of daisy chaining switches was introduced to minimize costs involved in controlling
them. A single-phase compensator, with this new topology and the new way of controlling switches,
was designed and built according to specifications stated by Eskom. This ultracapacitor-based dip
compensator was tested with a dip generator, developed by the University of Stellenbosch for
different load currents. The experimental results confirmed simulations made with identical
parameters. This thesis presents a reliable and cost effective solution for dip compensation. / AFRIKAANSE OPSOMMING: Hierdie tesis dek die ontwikkeling van ’n transformatorlose duik kompenseerder. Van al die bekende
toevoerkwaliteit probleme wek duike in die spanning die meeste kommer. Serie-injeksie
kompenseerders het die voordeel dat hulle net kompenseer vir die verlies in die toevoerspanning
tydens die duik. Dit het ’n beduidende vermindering in die omsetterkenwaardes en
energiestoorvereistes tot gevolg. Hierdie tesis mik om vorige soortgelyke ontwikkelings op te volg
en te verbeter met nuwe tegnologie om die funktionliteit te maksimeer. Die ontwerp is
geimplementeer met ultrakapasitore wat die onderhoudsvrye toestel ‘n leeftyd van 20 jaar toelaat.
Omdat ultrakapasitore so duur is moes ‘n nuwe topologie onwikkel word om die gebruik van
ultrakapasitore meer ekonomies aantreklik te maak. Daar is ook ‘n nuwe manier van skakelaar
beheer ontwikkel wat toelaat dat baie skakelaars oor een optise veesel beheer kan word. ‘n Enkel
fase dip kompensaeerder is toe onwikkel en gebou volgens Eskom se spesifikasies. Die
ultrakapasitor gebaseerde omsetter is getoets met ‘n dip generator wat deur die Universiteit van
Stellenbosch ontwikkel is. Die praktiese resultate bevestig die simulasies wat gedoen is met dieselfe
parameters. Hierdie tesis lei tot ‘n betroubaare en ekonomiese oplossing vir duik kompensasie.
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Parallel processing in power systems computation on a distributed memory message passing multicomputerHong, Chao, 洪潮 January 2000 (has links)
published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy
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An investigation of subsynchronous oscillation of AC/DC power systems: modeling and analysisYu, Chang., 余暢. January 2006 (has links)
published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy
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Use of Thyristor Controlled Series Capacitors (TCSCs) to enhance power system transient stability and their possible application on the South African GridGumunyu, Tonderayi January 2015 (has links)
This research report is submitted as a partial fulfilment of the requirements for a
Master of Science degree in Electrical Engineering (Power). / Thyristor Controlled Series Capacitors (TCSCs) are FACTS devices which
incorporate power-electronic-based and other static controllers to enhance
controllability and increase power transfer capability. This research investigated the
possibility of applying TCSCs on the South African transmission network, in
particular application on long transmission lines connecting bulk thermal generators
in the northern part of South Africa to load centres located hundreds of kilometres
elsewhere in the country. The investigation, conducted using PSS/E (a power
system analysis software) demonstrated that application of TCSCs on this part of
South African transmission network results in improved transient stability margins.
The resulting improvement in transient stability is comparable to other transient
stability enhancement options like addition of transmission lines, thus the use of
TCSCs can be considered as an alternative. Further studies would be vital to
understand the interaction between Power System Stabilizers (PSSs) and TCSCs in
order to ensure proper tuning and interaction amongst the devices. / MT2017
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An efficient algorithm using Householder's formulas for the solution of faulted power systemsAltamirano Chavez, Armando January 2010 (has links)
Digitized by Kansas Correctional Industries / Department: Electrical Engineering.
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Selective modal analysis with applications to electric power systemsPérez Arriaga, José Ignacio January 1981 (has links)
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 400-410. / by Jose Ignacio Perez Arriaga. / Ph.D.
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