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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Analysis and continuous simulation of secure-economic operation of power systems

Fahmideh-Vojdani, A. (Alireza) January 1982 (has links)
The present thesis, for the most part, is concerned with the application of continuous optimization to the secure-economic dispatching of thermal power plants. / The general concept of the continuous simulation of the optimum operation of power systems is introduced. This is the characterization of the solution trajectory of the underlying dispatching model as the loads vary along a forecasted trajectory, or as the system parameters continuously change. An efficient continuation algorithm is developed which characterizes the solution trajectory of a secure-economic dispatch model, given a piecewise linear trajectory of the bus loads, parameterized in terms of the system load. The algorithm considers piecewise quadratic generation cost functions, a DC load flow model, and the limits on generations and power flows in the normal and post transmission line outage states. The solution trajectory is provided in an analytic form over the entire loadability range of the system. Applications of the algorithms to systems with up to 118 buses show that it is fast, reliable, and well-suited for many applications in power system planning and operation. / The continuation algorithm, as the thesis describes, in essence applies the Incremental Loading procedure to the secure-economic dispatching. In this light, it can be viewed as a natural extension of the highly successful classical dispatching techniques such as Lambda Dispatching. A reexamination of the classical economic dispatching is presented early in the thesis. Highlights of this phase of the study include: generation scheduling with general (i.e., possibly non-convex) generation cost functions, an analytic study of the Valve Point Loading based on the general characterization of the valve loop based system incremental cost curve, an in-depth study of the system incremental cost in the context of the modified coordination equations, and a stochastic formulation and analysis of economic dispatching of regulating plants.
172

Real time steady state security assessment in electric power systems

Rodolakis, Anthony J. January 1984 (has links)
The present thesis tackles the problem of on-line steady state security assessment in electric power transmission networks. The contingencies examined include generation shift as well as line (transformer) outages. / The methodology developed is Pattern Recognition-motivated although not entirely within the frame of traditional statistical Pattern Recognition. / Due to the fact that training samples are rather expensive to obtain in electric power engineering, our first concern was to develop and implement algorithms carrying out the task of intelligently acquiring training points. It is found that these algorithms, permit to substantially reduce the amount of off-line computational effort while, at the same time, the coherency and impartiality of the information contained in the training sets is enhanced. / A new scheme for security assessment (equally applicable for real time security screening) was developed based on the concept of the hyperellipsoids of confidence. It is shown that by proper utilization of the hyperellipsoids of confidence, uncertainty in real time decision making (directly related to the misclassification error) is circumvented. The results of the new methodology were verified by full scale ac simulations. / Finally, the usefulness and potential applicability of the new scheme is demonstrated for EHV equivalents. Its merits are simplicity and reliability in real time environment.
173

Application of optimization methods for power system economic operation and transfer capability evaluation /

Shu, Chang, January 2003 (has links)
Thesis (M.Eng.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 123-127. Also available online.
174

Application of contingency analysis methods for power system security and optimization /

Sawhney, Ravinder Pal Singh, January 2004 (has links)
Thesis (M.Eng.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 109-113.
175

Investigation of interoperability of IEC 61850 protection functions

Mguzulwa, Ncedo Richard January 2018 (has links)
Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, [2018]. / Introduction of IEC 61850 standard defined substation automation system communication. The need of interoperability among the relevant devices coming from different vendors is a necessity to ensure utilities/municipalities obtain value for money. Vendors used their own proprietary tools to achieve communication in a substation. This caused an Intelligent Electronic Device (IED) from vendor A could not communicate with an IED from vendor B. Utilities/municipalities are forced to depend on single vendor solutions in a substation automation system. IEC 61850 systems tout Interoperability as a major gain in the Substation Automation System (SAS) environment. The implementation of interoperable systems in SAS environment requires extensive testing and careful selection of vendors. This involves extensive testing to meet the required requirements of a certain SAS. Interoperability implementation and testing methods need to be formulated and tested rigorously with various scenarios of interoperability in an SAS. GOOSE messages form the foundation of IEC 61850 standard as they are responsible for the copper-less connections for peer to peer communications. GOOSE messages are based on peer to peer communications to enable interoperability at the bay level which is called horizontal communication. IEDs need to be carefully selected to ensure GOOSE messaging interoperability is achieved. Test methods are equally important as methodology to achieve interoperability. The purpose of this research is to perform an investigation on interoperability of IEC 61850 conformant IEDs based on evaluation of their protection functions. The research looks at various vendors on how each has interpreted the IEC 61850 standard. Also an analysis on requirements to achieve interoperability is conducted. Investigation on various vendor independent system configuration tools to ease the implementation burden of a multivendor application is done. Evaluation into flexible object modelling and naming conventions in order to achieve interoperability is performed. Various tests using different tools to assess the integrity of interoperability are completed. The research delivers a methodology to evaluate and implement GOOSE message interoperability. The interoperability methodology can be used for improvement of interoperability applications. The methodology can also be implemented as procurement requirement to ensure interoperability. The evaluation/implementation of interoperability can be included in Factory Acceptance Test (FAT). The methodology to achieve interoperability is only usefully when requirements are clear with regard to what needs to achieved by SAS.
176

An integrated programme for power systems simulation using personal computers (PC's)

Atkinson-Hope, Gary January 1993 (has links)
Thesis (Masters Diploma (Technology)--Cape Technikon, Cape Town, 1993 / The research objectives were to: Formulate a training structure covering conventional power systems topics; Research existing PC based power systems software resources; Develop a structure for a PC based power systems course; Research the capabilities of the software resources chosen; Develop a structure for a modern PC based power systems course taking into account the capabilities and limitations of the selected software programs; Develop for the PC based power systems course, task orientated computer based laboratory set-ups. The set-ups provide: An introduction into the topics concerned; An explanation of the usage of each program applied, where usage means an explanation of the Input and Output Data of each program; User friendly simulation experiments. These set-ups, together with software programs and a personal computer integrate into a training programme and realize a power systems simulation course.
177

Performance analysis of a protection scheme based on P-class synchrophasor measurements

Mthunzi, Everett Mondliwethu January 2016 (has links)
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016. / Power grid and system protection advancement greatly depend on technological advances. Advent technologies like digital microprocessor type protective relays facilitate paradigm shifts, providing inimitable beneficial engineering adaptations. Phasor measuring technology provides one such technological advance. The onset and rapid development of the Phasor Measuring Unit (PMU) provides an excellent platform for phasor-based, power system engineering. Power transmission constitutes a critical section in the electric power system. The power system transmission lines are susceptible to faults which require instant isolation to establish and maintain consistent system stability. This research focuses on the study of transmission line protection based on P-Class synchrophasor measurements. The IEEE C37.238-2011 Precision Time Protocol (PTP) paradigm shift facilitates practical application of synchrophasors in protection schemes. Synchrophasor procession and accurate data alignment over wide areas support the hypothesis of a phasor-based transmission line differential protection. This research aims to directly implement P-Class synchrophasors in transmission line differential protection, employing synchrophasors to determine fault conditions and administer corresponding protective actions in wide area transmission lines. The research also aims to evaluate the operational characteristics of the synchrophasor-based transmission line differential protection scheme. The research deliverables include a laboratory scale Test-bench that implements the PMU-based transmission line differential protection scheme, and a differential protection utility software solution that follows guidelines specified by the C37.118-2011 standard for synchrophasors. The findings stand to evaluate performance of the PMU-based line differential protection scheme, verifying the protection model as an alternate, practical and feasible backup protection solution. The research deliverables include a synchrophasor-based current differential algorithm, software utility for implementing the PMU-based protection scheme and a Test-bench for concept and feasibility validation.
178

Analysis and continuous simulation of secure-economic operation of power systems

Fahmideh-Vojdani, A. (Alireza) January 1982 (has links)
No description available.
179

Real time steady state security assessment in electric power systems

Rodolakis, Anthony J. January 1984 (has links)
No description available.
180

A decision making tool for evaluating uncertainties in electric power system planning

Osareh, Ali Reza 06 June 2008 (has links)
Planning of today's electric utilities demand careful consideration of issues such as environment, demand-side management, non-utility generation, and new technologies which are subject to different constraints and uncertainties. Utilities have long developed and used models for their short and long-term planning, most of which are single purpose, large, data intensive, and do not fully account for uncertainties. New techniques have emerged to deal with uncertainties in utility planning. Among them, the Analytic Hierarchy Process (AHP) has been more successful in assessing uncertainties, and found to be well structured and applicable to individual as well as group decision makers. However, the results of this method are merely point estimate values. It is the objective of this research to identify a methodology which is capable of evaluating uncertainties with relative ease and accuracy without the need for a large volume of data and complicated software packages. The Analytic Hierarchy Process has been extended to estimate the variance of the error in judgments and therefore the confidence interval of values instead of point estimate values. A simulation study was carried out to check the accuracy of error variance (QI) in confidence interval calculations. The results showed that QI has a linear relationships with the variance of weights. The extended AHP method is applied to three case studies, including 1) Third party generation bidding evaluation criteria, 2) Identification and evaluation of different load management programs on utility peak reduction, and 3) Oil price prediction for electric utilities. This method promises to be an effective decision making tool for evaluating uncertainties in electric power system planning. / Ph. D.

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