• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 405
  • 215
  • 114
  • 17
  • 13
  • 9
  • 9
  • 7
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 1016
  • 1016
  • 306
  • 293
  • 226
  • 226
  • 220
  • 177
  • 166
  • 136
  • 119
  • 112
  • 112
  • 105
  • 104
  • 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.
81

Design of secondary voltage and stability controls with multiple control objectives

Song, Yang. January 2009 (has links)
Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Begovic, Miroslav; Committee Member: Deng, Shijie; Committee Member: Divan, Deepakraj; Committee Member: Harley, Ronald; Committee Member: Lambert, Frank; Committee Member: Shamma, Jeff. Part of the SMARTech Electronic Thesis and Dissertation Collection.
82

Telecommunication of stabilizing signals in power systems

Raux, Guillaume J. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains vii, 51 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 50-51).
83

Stability of a 24-bus power system with converter interfaced generation

Weldy, Christopher 08 June 2015 (has links)
The objective of this Masters Thesis is to investigate the system stability implications of integration of power electronic converter interfaced generation (CIG) into conventional power systems. Due to differences between conventional generation and (CIG), the power system fault currents, voltage response, and frequency response will likely change with increased penetration of (CIG). This research has employed state of the art software tools to perform simulations on the IEEE 24-Bus Reliability Test System (RTS-24), appropriately modified to include converter interfaced generation. Time-domain dynamic simulations and fault calculations have been performed for the system. A comprehensive set of simulations has been performed on the base case, comprised entirely of conventional generation. Conventional generation was replaced by (CIG) in the model, one generating station at a time until (CIG) penetration reached one-hundred percent. The comprehensive set of simulations has been performed at each level of (CIG) penetration. The results have been compared to the base case, with a focus on voltage response, frequency response, and fault current levels of the power system.
84

Electric transmission system expansion planning for the system with uncertain intermittent renewable resources

Park, Heejung 30 January 2014 (has links)
This dissertation proposes a new transmission planning method for electric power systems with large planned additions of uncertain intermittent renewable resources. The major contribution of this dissertation is applying stochastic programming that represents two uncertain parameters, wind and load, to transmission planning. We apply an ad hoc partition method to approximate the bivariate random variables of load and wind. A two-stage stochastic transmission planning problem is repeatedly solved by replacing continuous random variables with approximations that have a more refined partition at each iteration. A candidate solution is provided when improvement is not observed at an optimal value, even with more refined approximations. Numerical results show the efficiency of the method. However, if the number of samples is not sufficient to represent the original random variable's characteristics, the solution may be poor. Therefore, we employ a sampling method using Gaussian copula in order to generate as many random samples as necessary. The problem is replicated and solved using a fixed number of samples generated by Gaussian copula. In order to asses solution quality, a 95\%-confidence interval on the optimality gap is formed. A candidate stochastic solution for transmission investment is used to simulate the operation of a utility-scale storage system. A mixed integer program (MIP) is applied to this formulation. As a case study, the Electric Reliability Council of Texas (ERCOT) wind and load data is employed, along with a simplified model of the transmission system. Energy storage is also considered. The storage operation shifts wind power from off-peak hours to on-peak hours, and its wind power generation shows a close character to that of a base load generator. / text
85

Enhancing transient stability of power systems using a thyristor controlled series capacitor.

January 2005 (has links)
The continuously growing demand for electric power requires transmitting larger amounts of power over long distances. An economically attractive solution to increase the power transfer through a long interconnection (up to a limit) without building new parallel circuits is to install series capacitor compensation on the transmission line. Large disturbances which constantly occur in power systems may disrupt the synchronous operation of the generators and lead to out-of-step conditions. Coordinated insertion and removal of the compensating capacitors in series with a transmission line is an approach that has been known for many years to be capable of enhancing the transient stability of power systems as well as providing additional damping to the power system oscillations. The relatively recent emergence of the thyristor controlled series capacitor (TCSC) has now made this method of transient stability enhancement practically feasible. This thesis compares a range of different strategies that have been proposed in the literature for control of series compensating reactance to enhance transient stability. Initially a simple swing-equation model of a single-generator power system, including an idealised controllable series compensator (CSC) is used to study the fundamental characteristics of the variable impedance control and its impact on transient stability. Subsequently, a detailed model of a small study system is developed, including a detailed representation of a TCSC, for more in-depth analysis. This detailed study system model is then used to compare three different transient stability control schemes for the TCSC, namely: generator speed-deviation based bang-bang control, discrete control based on an energy-function method, and nonlinear adaptive control. Time-domain results are presented to demonstrate the impact of the TCSC on first swing stability of the SMIB system with the above control schemes for various fault scenarios. The performance of each control scheme is also compared by evaluating the extent to which it extends the transient stability margin of the study system. For each of the three different TCSC control approaches considered, the results show that variable impedance control of the TCSC provides further improvement in the transient stability limits of the study system over and above the improvement that is obtained by having a fixed-impedance TCSC in the system. In the case of the bangbang and discrete control approaches, it is shown that a combination of a large steady state value of the TCSC compensation, together with a relative small range of variable TCSC reactance under transient conditions, offers. the best improvement in the transient stability limits for the studied system. The results also show that there is little difference in the extent to which the energy function method of TCSC control improves the transient stability limits over the improvement obtained using speed-deviation bang-bang control of the TCSC for the study system considered. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2005.
86

Using computer graphics to demonstrate distant relay operation under transient conditions

Mwase, Naomi January 1992 (has links)
Thesis (MEng) -- University of South Australia, 1992
87

Using computer graphics to demonstrate distant relay operation under transient conditions

Mwase, Naomi January 1992 (has links)
Thesis (MEng) -- University of South Australia, 1992
88

Using computer graphics to demonstrate distant relay operation under transient conditions

Mwase, Naomi January 1992 (has links)
Thesis (MEng) -- University of South Australia, 1992
89

Utilizing microprocessor based relays as predictive tools to mitigate voltage instability problems that stem from the fast voltage collapse and delayed voltage recovery phenomena

Olajubutu, Michael Olaolu. January 2007 (has links) (PDF)
Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 49)
90

A comprehensive approach to reactive power scheduling in restructured power systems : a dissertation presented to the faculty of the Graduate School, Tennessee Technological University /

Shukla, Meera, January 2007 (has links)
Thesis (Ph.D.)--Tennessee Technological University, 2007. / Bibliography: leaves 108-114.

Page generated in 0.0661 seconds