search query: @keyword kalibrointi / total: 67
reference: 28 / 67
« previous | next »
Author:Kara, Olli
Title:Välkyntämittareiden kalibrointimenetelmän kehittäminen
Development of a Calibration Method for Flickermeters
Publication type:Master's thesis
Publication year:2007
Pages:74      Language:   fin
Department/School:Sähkö- ja tietoliikennetekniikan osasto
Main subject:Sähköverkot ja suurjännitetekniikka   (S-18)
Supervisor:Lehtonen, Matti
Instructor:Hällström, Jari
Electronic version URL: http://urn.fi/urn:nbn:fi:tkk-009663
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 S80     | Archive
Keywords:power quality
flicker
flickermeter
calibration
sähkön laatu
välkyntä
välkyntämittari
kalibrointi
Abstract (eng):Flicker is a power quality issue which is caused by rapid fluctuations of supply voltage.
The most common sources of voltage fluctuations are large loads which take rapidly changing inductive power from the supplying power system.
Of all electric equipment, lamps are most sensitive to voltage fluctuations.
Flicker is already perceptible for fluctuation levels of the order of a few percent.

A flickermeter is a device that measures the voltage and thus evaluates the flicker perceptibility.
This is done by simulating the behavior of lamp, eye and brain.
A flickermeter also performs a statistical analysis for ten minute periods of the perceptibility data.
The result of the statistical analysis is flicker severity index (Pst).
Value 1 of the severity index corresponds with the irritability threshold of an average human observer.
Long term flicker severity (Plt) is calculated from successive Pst-readings.
International standard IEC 61000-4-15 defines the functional and design specifications of the flickermeter.

For the master's thesis a method and equipment for calibration of flickermeters is developed.
The method is based on reference flickermeter, which is constructed according to the standard as closely as possible.
The uncertainty of the flickermeter is estimated and the system is tested by calibrating a commercial power quality analyzer.
Abstract (fin):Välkyntä on sähkön laatuongelma, joka johtuu sähköverkon jännitteen nopeista vaihteluista.
Niitä aiheuttavat pääasiassa suuret kuormat, joiden verkosta ottama teho vaihtelee huomattavasti suhteessa verkon oikosulkutehoon kuorman kytkentäpisteessä.
Jännitteen vaihteluiden haitoista suurin on valojen välkyntä, jota esiintyy jo hyvin pienillä, alle prosentin jännitteen vaihteluilla.

Välkyntämittari on laite, joka mittaa sähköverkon jännitettä ja arvioi mittauksen perusteella valaistuksen välkynnän havaittavuuden.
Tämä tapahtuu simuloimalla lampun, silmän ja aivojen toimintaa.
Lisäksi välkyntämittari laskee tilastollisesti välkynnän häiritsevyysindeksin (Pst) kymmenen minuutin mittausjaksoille.
Häiritsevyysindeksin arvo 1 vastaa koehenkilöiden avulla määritettyä välkynnän häiritsevyyskynnystä.
Pidemmän ajan häiritsevyysindeksi (Plt) lasketaan peräkkäisistä Pst-arvoista.
Välkyntämittarin rakenteen ja toiminnan määrittelee kansainvälinen standardi IEC 61000-4-15.

Diplomityössä on kehitetty menetelmä ja laitteisto välkyntämittareiden kalibrointia varten.
Menetelmä perustuu referenssimittariin, joka on rakennettu mahdollisimman tarkasti standardin mukaan ja jonka epävarmuutta on arvioitu.
Laitteiston käyttöä on kokeiltu myös kaupallisen sähkönlaatuanalysaattorin kalibrointiin.
ED:2007-08-22
INSSI record number: 34466
+ add basket
« previous | next »
INSSI