search query: @keyword tree / total: 3
reference: 2 / 3
« previous | next »
Author:Omidiora, Michael Adebayo
Title:Lightning overvoltage studies in medium voltage distribution lines
Publication type:Master's thesis
Publication year:2008
Pages:78 + (13)      Language:   eng
Department/School:Elektroniikan laitos
Main subject:Sähköverkot ja suurjännitetekniikka   (S-18)
Supervisor:Lehtonen, Matti
Instructor:Lehtonen, Matti
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
Instructions

Reading digital theses in the closed network of the Aalto University Harald Herlin Learning Centre

In the closed network of Learning Centre you can read digital and digitized theses not available in the open network.

The Learning Centre contact details and opening hours: https://learningcentre.aalto.fi/en/harald-herlin-learning-centre/

You can read theses on the Learning Centre customer computers, which are available on all floors.

Logging on to the customer computers

  • Aalto University staff members log on to the customer computer using the Aalto username and password.
  • Other customers log on using a shared username and password.

Opening a thesis

  • On the desktop of the customer computers, you will find an icon titled:

    Aalto Thesis Database

  • Click on the icon to search for and open the thesis you are looking for from Aaltodoc database. You can find the thesis file by clicking the link on the OEV or OEVS field.

Reading the thesis

  • You can either print the thesis or read it on the customer computer screen.
  • You cannot save the thesis file on a flash drive or email it.
  • You cannot copy text or images from the file.
  • You cannot edit the file.

Printing the thesis

  • You can print the thesis for your personal study or research use.
  • Aalto University students and staff members may print black-and-white prints on the PrintingPoint devices when using the computer with personal Aalto username and password. Color printing is possible using the printer u90203-psc3, which is located near the customer service. Color printing is subject to a charge to Aalto University students and staff members.
  • Other customers can use the printer u90203-psc3. All printing is subject to a charge to non-University members.
Location:P1 Ark TKK  2542   | Archive
Keywords:lightning strokes
lightning overvoltages
MOV arresters
ATP/EMTP
test feeder
distribution line
exposure-arc (EA)
electro-geometric model
tree
Abstract (eng): This research work involves simulations, laboratory experiments and statistical analyses of lightning overvoltages in MV distribution lines.
The present understanding of lightning models and the nature of lightning overvoltages are also critically investigated and evaluated.
All simulations are carried out with reference to fast transient simulation guidelines as specified in the lightning literature.

In the experimental work, the electrical breakdown characteristics of lightning impulse voltages are observed on both the tree and the grounded conductor with variations in the striking distances from the lightning electrode to the two objects.
This is used to determine the attractiveness of the tree on direct strokes to the grounded conductor.
A calibration constant is extracted, which corresponds to the probability of occurrence of direct strokes to both the tree and the grounded conductor being equal.
This constant is then incorporated in the electro geometric model to determine the influence of tree height on the exposure arc of a grounded conductor.
The experimental result is compared with similar work available in the literature.

Finally, the statistical analyses are performed in order to estimate the lightning performance level of the two existing distribution line designs in Finland, which are overhead lines and covered conductors, and also investigate improvements.
ED:2008-03-13
INSSI record number: 35424
+ add basket
« previous | next »
INSSI