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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.
261

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.
262

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.
263

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.
264

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.
265

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.
266

Real options theory applied to renewable energy generation projects planning

Martinez-Cesena, Eduardo Alejandro January 2012 (has links)
The existing environmental threats and the ever increasing global dependence on electric power highlight the importance of producing power in a sustainable manner. In accordance, it is vital to attract investments in electricity generation projects based on renewable energy sources, also called renewable energy projects (REP). This poses a challenge, as REP tend to be less financially competitive than their fossil fuel based counterparts. Moreover, the power grid has to be upgraded to integrate large amounts of RESs in an efficient and economic manner. An appealing alternative to enhance the financial appealing of REP is to improve the techniques used for their assessment. These tools produce robust and economically sound assessments, but tend to undervalue REP and other projects under uncertainty, as they neglect the flexibility of the projects to be adjusted in response to uncertainty. This can be corrected by extending the tools with the aid of real options (RO) theory. RO theory can be used to extend assessment techniques to value flexibility derived from the projects, their management, and even their environment, which can be used to enhance the financial value of REP in the changing power sector. In addition, the scope of RO theory is increasing to address flexibility in the design of the projects. Therefore, the theory can drive investments in REP and motivate the design of more profitable projects. This research project seeks to analyse the potential of RO theory to increase the financial worth of different types of REP in the current and changing power sector. The novelties of this research are that it expands RO theory by addressing the flexibility within the design of the projects, the potential of RO theory to manage uncertainties that are exclusive to the projects or typical in the power sector, and other relevant areas of research interest. The research produced several RO methodologies to model the planning, operation, and design of hydropower projects, wind power projects, and solar photovoltaic projects in existing power sector environments and environments characterised by high penetration of RESs and consumers with demand response capabilities. The results demonstrate the applicability of RO theory to enhance the financial value of different types of REP under a wide range of circumstances.
267

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

Fahmideh-Vojdani, A. (Alireza) January 1982 (has links)
No description available.
268

Real time steady state security assessment in electric power systems

Rodolakis, Anthony J. January 1984 (has links)
No description available.
269

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.
270

Development Of Algorithms For Power System State Estimation Incorporating Synchronized Phasor Measurements

Kumar, V Seshadri Sravan 01 1900 (has links) (PDF)
The ability to implement Wide Area Monitoring and Control in power systems is developing into a need in order to prevent wide scale cascading outages. Monitoring of events in the power system provides a great deal of insight into the behaviour of the system. The research work presented in this thesis focussed on two tools that aid in monitoring: State Estimation and Synchronised Phasors provided by Phasor Measurement Units (PMU). State Estimation is essentially an on-line data processing scheme used to estimate the best possible state (i.e. voltage phasors) from a monitored set of measurements (active and reactive powers/voltage phasor measurements). The ever growing complexity and developments in the state of art calls for robust state estimators that converge accurately and rapidly. Newton’s method forms the basis for most of the solution approaches. For real-time application in modern power systems, the existing Newton-based state estimation algorithms are too fragile numerically. It is known that Newton’s algorithm may fail to converge if the initial nominal point is far from the optimal point. Sometimes Newton’s algorithm can converge to a local minima. Also Newton’s step can fail to be a descent direction if the gain matrix is nearly singular or ill-conditioned. This thesis proposes a new and more robust method that is based on linear programming and trust region techniques. The proposed formulation is suitable for Upper Bound Linear Programming. The formulation is first introduced and its convergence characteristics with the use of Upper Bound Linear Programming is studied. In the subsequent part, the solution to the same formulation is obtained using trust region algorithms. Proposed algorithms have been tested and compared with well known methods. The trust region method-based state estimator is found to be more reliable. This enhanced reliability justifies the additional time and computational effort required for its execution. One of the key elements in the synchrophasor based wide area monitoring is the Phasor Measurement Unit. Synchronized, real time, voltage phasor angle, phasor measurements over a distributed power network presents an excellent opportunity for major improvements in power system control and protection. Two of the most significant applications include state estimation and instability prediction. In recent years, there has been a significant research activity on the problem of finding the suitable number of PMUs and their optimal locations. For State Estimation, such procedures, which basically ensure observability based on network topology, are sufficient. However for instability prediction, it is very essential that the PMUs are located such that important/vulnerable buses are also directly monitored. In this thesis a method for optimal placement of PMUs, considering the vulnerable buses is developed. This method serves two purposes viz., identifying optimal locations for PMU (planning stage), and identifying the set PMUs to be closely monitored for instability prediction. The major issue is to identify the key buses when the angular and voltage stability prediction is taken into account. Integer Linear Programming technique with equality and inequality constraints is used to find out the optimal placement set. Further, various aspects of including the Phasor Measurements in state estimation algorithms are addressed. Studies are carried out on various sample test systems, an IEEE 30-bus system and real life Indian southern grid equivalents of 24-bus system, 72-bus system and 205-bus system.

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