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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.
91

Improved dynamic stability using FACTS devices with phasor measurement feedback /

Smith, Mark Allen. January 1994 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 82-83). Also available via the Internet.
92

Pattern recognition methodology for network-based diagnostics of power quality problems /

Wang, Min, January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 134-140).
93

A critical study of methods of solving power system transient stability problems

Das Gupta, Sushil. January 1957 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1957. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 154-156).
94

Direct transient stability margin assessment of power system with excitation control and SVC control /

Cheung, Siu-pan. January 1996 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references.
95

Decoupling and stabilizing control of multi-machine power systems with static VAr compensators /

Tsang, Kwan-ming. January 1900 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1993.
96

Selection of pilot buses for VAR support and voltage stability risk analysis

Lakkaraju, Talpasai. January 2006 (has links)
Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xi, 94 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 90-94).
97

An Investment Planning Model for a Battery Energy Storage System - Considering Battery Degradation Effects

January 2014 (has links)
abstract: As global energy demand has dramatically increased and traditional fossil fuels will be depleted in the foreseeable future, clean and unlimited renewable energies are recognized as the future global energy challenge solution. Today, the power grid in U.S. is building more and more renewable energies like wind and solar, while the electric power system faces new challenges from rapid growing percentage of wind and solar. Unlike combustion generators, intermittency and uncertainty are the inherent features of wind and solar. These features bring a big challenge to the stability of modern electric power grid, especially for a small scale power grid with wind and solar. In order to deal with the intermittency and uncertainty of wind and solar, energy storage systems are considered as one solution to mitigate the fluctuation of wind and solar by smoothing their power outputs. For many different types of energy storage systems, this thesis studied the operation of battery energy storage systems (BESS) in power systems and analyzed the benefits of the BESS. Unlike many researchers assuming fixed utilization patterns for BESS and calculating the benefits, this thesis found the BESS utilization patterns and benefits through an investment planning model. Furthermore, a cost is given for utilizing BESS and to find the best way of operating BESS rather than set an upper bound and a lower bound for BESS energy levels. Two planning models are proposed in this thesis and preliminary conclusions are derived from simulation results. This work is organized as below: chapter 1 briefly introduces the background of this research; chapter 2 gives an overview of previous related work in this area; the main work of this thesis is put in chapter 3 and chapter 4 contains the generic BESS model and the investment planning model; the following chapter 5 includes the simulation and results analysis of this research and chapter 6 provides the conclusions from chapter 5. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2014
98

Aspects of the ratio of reactive to real powers as input to transmission network control

Swart, Sarica Meyer 05 June 2012 (has links)
D.Ing. / Transmission networks change continuously when new supply requests are made, network reinforcements are installed and equipment configuration changes. Therefore, network design, operation and control requirements change. To manage this, controllers are being developed to assist human network controllers who might not always be specialists in equipment operation and characteristics. A transmission network comprises multiple variables, some dependent on others. The resistive portion of a load (PLoad) and the total reactive power (Q) installed close to the load can be set in relation to each other. This relationship forms the basic concept of the QP ratio for a transmission network. This ratio is not standardly used as a variable in network operation or control. This thesis explores this new QP ratio in more depth for application in different networks. This concept is developed and investigated in detail and equations are derived from first principles. The usability of the QP ratio is described and calculations are done for existing networks. It is shown that each network has its own unique QP ratio that can be used as information for human operators or as part of a controller device. This information can assist in determining actions required to be taken by controllers and operators. This thesis investigates aspects related to the use of a QP ratio in transmission networks as far as system operation and network control is concerned. The information provided in this thesis could be developed further to assist in implementing of the QP ratio in transmission network control rooms or systems. This will contribute to the provision of more reliable, robust and controlled electrical networks.
99

Aspects of the ratio of reactive to real powers as input to transmission network control

Swart, Sarica Meyer 18 February 2014 (has links)
M.Ing. (Electrical Engineering) / Induction heating has been used in practice for many years. The main goal of this study is to investigate the use of a single-turn coil in a typical induction heater. The work starts off with a background study of elecrroheat and specifically high-frequency induction heating. Finite element simulations were conducted on different coil shapes and compared with each other. The converter. with control and driver circuits. used in the, experimental setup, as well as the experimental construction and results are described. The work is concluded with an evaluation of the project.
100

The value and risk of probabilistic thermal uprating scenarios on power system reliability

Tumelo-Chakonta, Chomba January 2015 (has links)
According to the European Network of Transmission System Operators for Electricity (ENTSO-E) there is a need to invest 104 billion Euros to either refurbish or construct overhead lines (OHLs). This massive enterprise is mainly driven by the need to accommodate the proliferation of renewable energy generation projects across Europe in response to the European Commission’s directive to supply 20% of its energy from renewables by the year 2020. However, 30% of transmission projects experience delays; and moreover, it has been found that if the existing grid capacity is to be increased by about 1.3% it would facilitate about 3% of renewables. Therefore, attention towards the thermal uprating of existing networks has attracted research interest. In this thesis, the main contribution to this research is a probabilistic and holistically integrated system and OHL plant reliability centred thermal uprating evaluation methodology. This methodology is designed to aid the facilitation of the thermal uprating’s of existing lines, through a variety of multistage and multifaceted risk based decisions. These multifaceted aspects are subject to the conflicting views to thermal uprating which stem from various utility personnel; which further stem from their constricted views on system reliability. For example, plant maintainers may resist thermal uprating because it may require the need to increase maintenance works on right-of-ways, or because they may need to prevent conductors from ageing sooner than initially projected. However, restricting thermal uprating for these reasons will limit the capability of the system to facilitate renewables, and this will negatively affect overall system reliability. Therefore, the presented methodology aids to facilitate highly efficient interdependent decision making amongst plant designers and maintainers, and system planners and operators, to effectively manage thermal uprating risks in consideration to the overall utility’s goals. This thesis implements a variety of studies to enlighten utility personnel of the possible economic benefits and risk mitigation practices that could be realised through thermal uprating. To present robustly conclusive and compelling results, these studies research the value of thermal uprating from three possible time scales: long-, medium- and short-term time domains. Consequently, planners (through this methodology) will for the first time ascertain the true value of (1) uprating existing conductors by accepting the subsequent acceleration of their ageing, (2) selecting the optimal reconductoring technology from a suite of candidate (conventional and novel) conductor technologies, (3) the retensioning policy to implement (at a particular stage of a project) in order to maintain reliability, and (4) novel real-time OHL ageing management tools for power system operators to use reliably.

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