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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.
11

Control of reactive compensation on transmission systems

Gaeb, Jassim Abdulah January 1989 (has links)
No description available.
12

Harmonic response of transmission systems with reactive compensation

Satapathy, J. K. January 1988 (has links)
No description available.
13

General curvilinear orthogonal meshes for use in TLM diffusion applications

Austin, John Dawson January 1991 (has links)
No description available.
14

Meshing techniques for TLM diffusion problems

Witwit, Abdul-Mehdi Rahim Mohammed January 1994 (has links)
No description available.
15

ESTIMATION OF TRANSMISSION LINE PARAMETERS USING LINEAR METHOD WITH SYNCHRONIZED AND UNSYNCHRONIZED DATA

Lahmar, Mustafa 01 January 2019 (has links)
Accurate value of transmission line parameters is important for power system protection applications, especially for distance relays whose zone settings are based on positive sequence line impedance. The research is devoted to estimating transmission line positive-sequence parameters from synchronized or unsynchronized measurements of voltage and current phasors that are obtained at both terminals of the line. The positive sequence parameters including series impedance and shunt admittance can be linearly estimated. The linear least square algorithm has been derived in this dissertation for different transmission line configurations. The algorithm is able to handle both synchronized and unsynchronized measurements and deal with potential synchronization errors by explicitly modeling the synchronization angle. Sample results are reported to demonstrate the effectiveness of the proposed method. Three types of transmission line models depending on line length (long, medium and short) are studied in this dissertation. Chapter 3 uses unsynchronized data for the long transmission line. The derived method can detect the unsynchronized angle and estimate the positive sequence of long line parameters. The proposed method is examined with negative impacts such as errors on currents and voltages data. These errors are added randomly to one set each time to test the robustness of the developed algorithm. The medium transmission line algorithm derivation is presented in chapter 4. This chapter uses a linear least square to estimate the lumped parameters of a medium transmission line. The two different transmission line circuits are used to model the medium line. The first circuit is a single transmission line with two nodes and is used to evaluate the developed algorithm. The second circuit is a double transmission line. These two lines can have the same or different line parameters or line length. The developed algorithm shows that the proposed method achieves highly accurate results for the estimation of positive sequence line parameters. The short transmission line is studied in chapter 5. The short transmission line uses less data than the long or medium lines because in this model the shunt capacitance is omitted. Thus, the linear estimation yields highly accurate results. Case studies are considered to test the robustness of this developed method. The line temperature mainly affects the series resistance, and the developed algorithms in previous three chapters can accurately estimate the transmission line parameters. To simplify the real-time estimation of line resistance and temperature, the series inductance, and shunt capacitance can be treated as constant and known values. Chapter 6 provides such studies of estimating resistance by treating inductance and capacitance as known values.
16

The impact on transmission line terminations on radiated emissions

Wong, Wei-Juet January 2007 (has links)
Terminating transmission lines at either the source or the load end with a damping resistor is frequently used to improve the signal integrity of clock or control lines on printed circuit boards. While a number of termination variants may produce similar results in regards to signal integrity, the electromagnetic compatibility performance can vary due to different current and voltage distributions along the line. This thesis investigates the impact of transmission line terminations on radiated emissions.
17

High speed digital protection of EHV transmission lines using traveling waves

Sidhu, Harjinder Singh 04 May 2004
Extra High Voltage (EHV) transmission lines are designed to transfer large amount of power from one location to another. The length exposed to the environment is a major reason for occurrence of faults on the lines. A fault on a high voltage transmission line affects the stability of the overall power system, which sometimes leads to permanent damage of the equipment. Relays are developed and installed to protect the lines. The transmission line protection relays, in the industry, are based on the fundamental frequency components of the voltages and currents. These relays need at least one fundamental frequency cycle for performing the protection operation. Voltage and current traveling waves are generated when a fault occurs on the transmission line. The velocity of propagation of traveling waves is finite and the level of the waves decreases with increase in the distance traveled. Information about the fault can be obtained by analyzing the traveling waves. A few traveling wave techniques, which are based on analog signal processing, to protect transmission lines have been proposed in the past. Two digital techniques, which use traveling waves for protecting EHV transmission lines, are proposed in this thesis. The traveling waves are extracted from the modal voltages and currents at the terminals of the transmission line. The techniques identify and locate the fault by using the information contained in the waves. A power system was modeled in the Electromagnetic Transient Direct Current Analysis (EMTDC) and several cases were created by varying different parameters related to the fault, fault type, fault location, fault resistance and fault inception angle. The techniques were implemented in hardware and their performance was tested on data, generated from the EMTDC simulations. Some cases are discussed in the thesis. The performance of the digital techniques for protecting EHV transmission lines using traveling waves was confirmed to be satisfactory. The proposed techniques provide protection at speed and discriminate well between internal and external faults.
18

High speed digital protection of EHV transmission lines using traveling waves

Sidhu, Harjinder Singh 04 May 2004 (has links)
Extra High Voltage (EHV) transmission lines are designed to transfer large amount of power from one location to another. The length exposed to the environment is a major reason for occurrence of faults on the lines. A fault on a high voltage transmission line affects the stability of the overall power system, which sometimes leads to permanent damage of the equipment. Relays are developed and installed to protect the lines. The transmission line protection relays, in the industry, are based on the fundamental frequency components of the voltages and currents. These relays need at least one fundamental frequency cycle for performing the protection operation. Voltage and current traveling waves are generated when a fault occurs on the transmission line. The velocity of propagation of traveling waves is finite and the level of the waves decreases with increase in the distance traveled. Information about the fault can be obtained by analyzing the traveling waves. A few traveling wave techniques, which are based on analog signal processing, to protect transmission lines have been proposed in the past. Two digital techniques, which use traveling waves for protecting EHV transmission lines, are proposed in this thesis. The traveling waves are extracted from the modal voltages and currents at the terminals of the transmission line. The techniques identify and locate the fault by using the information contained in the waves. A power system was modeled in the Electromagnetic Transient Direct Current Analysis (EMTDC) and several cases were created by varying different parameters related to the fault, fault type, fault location, fault resistance and fault inception angle. The techniques were implemented in hardware and their performance was tested on data, generated from the EMTDC simulations. Some cases are discussed in the thesis. The performance of the digital techniques for protecting EHV transmission lines using traveling waves was confirmed to be satisfactory. The proposed techniques provide protection at speed and discriminate well between internal and external faults.
19

Proposed Manitoba Hydro D.C. transmissionline east of Lake Winnipeg: Identification of alternative corridors with a view to minimize adverse effects on outdoor recreation

Asgarali, Ashmede S.J. 28 August 2015 (has links)
A regional assessment of the potential impacts of transmission facilities on the area east of Lake Winnipeg was conducted in order to identify alternative transmission corridors with the emphasis on minimizing the adverse effects on outdoor recreation. A regional resource inventory of the Biotic, Socio-cultural, and Recreational Components of the study area was assembled. Impacts of severe, high, moderate and low were defined and applied to the resource inventory. Four possible corridor routes; --A, B, C and D --were identified at the northern extent of the study area, converging to three just south of the fifty-second parallel; one with its associated trunk line along the east shore of Lake Winnipeg, the other with its associated trunk line along the midline of the study area and the third, along the Manitoba-Ontario border veering southeast to a common exit near the Fort Alexander Indian Reserve. Finally, the corridor on the east shore of Lake Winnipeg and the central corridor converge in the Manigotagan area and exit the study area near the Fort Alexander Indian Reserve. / October 2015
20

COMPREHENSIVE TECHNIQUES TO DETERMINE BROADBAND PHYSICALLY-CONSISTENT MATERIAL CHARCTERISTICS USING TRANSMISSION LINES

Zhou, Zhen January 2009 (has links)
Dispersion, attenuation, and crosstalk are several major challenges that both a high-speed digital and a microwave serial link must overcome to achieve their desirable performance. These phenomena are directly related to the frequency dependency of the dielectric property of the material used in package and interconnect. The dielectric property of a material is commonly measured by its manufacturer in a particular direction at a few discrete frequencies using resonator and waveguide methodology. Since the dielectric property may vary during manufacturing processing, the measurements taken by the manufacturer might be not adequate. Moreover, the dielectric property of a material in a bandwidth that covers at least the second harmonics of the fundamental operational frequency is required to accurately predict the link performance. One of the efforts in this research is to investigate the methodology of realizing broadband characteristics of the dielectric property of a material in its "as packaged" configuration using various transmission line topologies, such as microstrip line and Co-Planar Waveguide (CPW). Transitions from CPW to other transmission line topologies are mandatory if CPW probes are used to achieve broadband and repeatable measurements. Since microstrip line is one of the transmission line topologies involved in this research, a research effort is dedicated to develop a broadband CPW-to-microstrip line transition. An effort is also expended to creating casual material models that can be used in electromagnetic simulators to appropriately model the link based on the polarization mechanism of the materials. In addition to focusing on the measurement method in frequency domain, Short Pulse Propagation (SPP), a time domain method, is investigated as well. A virtual test bench is created to investigate the correlation between impedance variations in stripline structures due to fabricated tolerance and the attenuation predicted by SPP.

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