- Type of paper
: Paper in journal
Title: POWER TRANSFORMERS MAINTENANCE
- Authors:
- Mikulecky, Antun
- Čabrajac, Sonja (7516)
Journal: Energija
Number: 6
ISSN: 0013-7448
Volume: 40
Year: 1991
Pages: from 389 to 397
Number of references: 6
Language: hrvatski
Summary: Suitable power transformer maintenance is one of
thepreconditions of its reliable service. It includes both thecontrol
(state diagnosis) and the transformer maintenance. Inthis work, diagnosis
methods and procedures are described, thatcan be applied when transformers
are operating and the frequencyof those methods is recommended. The basic
maintenance ofsignificant power transformer components are also described.
Thiswork is the result of a long-time transformer behaviourobservation, the
study of transformer faults, literature andregulations and it should be
considered a reminder on oilimmersedpower transformer maintenance.
Keywords: High power transformers maintenance, diagnostic testing, insulating system, surveillance
- Type of paper
: Paper in journal
Title: PROTECTIVE INSULATING SHUTTERS AS PROTECTION IN LIVE-LINE
WORKING IN THE MEDIUM-VOLTAGE SWITCHGEAR
- Authors:
- Firinger, Vladimir (12014)
- Polak, Josip (68325)
- Pavić, Ante
Journal: Energija
Number: 3
ISSN: 0013-7448
Volume: 44
Year: 1995
Pages: from 149 to 152
Number of references: 5
Language: hrvatski
Summary: The requirements, design, usage and maintenance of
protective insulating shutters that serve as protection in live-line workig
in the medium-voltage switchgears are presented in the paper.
Keywords: Medium-voltage switchgear, protective insulating shutters, insulating materials
- Type of paper
: Paper in proceedings
Title: DIAGNOSTICS OF INSULATING SYSTEMS OF ELECTRIC MACHINES
- Authors:
- Firinger, Vladimir (12014)
- Editors
- Srb, Neven
Proceedings title: Zbornik radova: 3. Međunarodni Simpozij o novim tehnologijama; Tem.podr.01-07
Language: hrvatski
Place: Opatija
Year: 1991
ISBN/ISSN: 86-81997-01-7
Pages: from 21 to 21
Meeting: 3. Međunarodni simpozij o novim tehnologijama SONT
Held: from 10/15/91 to 10/17/91
Summary: Since the eighties, monitoring and diagnostics of
electricmachines have provided additional up-to date, comprehensiveand very
useful methods that ensure higher reliability andusefulness of machines.
They also reduced the influence of humanfactor on large power systems.
The diagnostic methods serve for:
- monitoring and detection of the state of insulating system,
- detection of degradation level and mechanisms,
- determination of spent and remaining life,
- detection of weak spots and damages before serious troubles,
- detection of trouble location and level.
Keywords: Electrotechnik, electrical machines, electrical rotating machines, transformers, insulating materials, insulating systems, diagnostics, technical diagnostics
- Type of paper
: Paper in proceedings
Title: THE INFLUENCE OF TEST CONDITIONS OF MATERIAL MEASUREMENTS
ON DESIGN AND DIAGNOSTIC PARAMETERS
- Authors:
- Firinger, Vladimir (12014)
- Editors
- Srb, Neven
Proceedings title: Zbornik radova: 3. Međunarodni Simpozij o novim tehnologijama: Tem.podr.:01-07
Language: hrvatski
Place: Opatija
Year: 1991
ISBN/ISSN: 86-81997-01-7
Pages: from 37 to 42
Meeting: 3. Međunarodni simpozij o novim tehnologijama SONT
Held: from 10/15/91 to 10/17/91
Summary: The constant developmemt of more economic electrical
equipmentdesignes and the usage of more sophisticated tests require
aconstant improvement of accuracy of determination of measuringresults of
material properties that are used as computationinputs. The imput data for
computation of limit values ofmachines, as well as those used for
forecasting must be of thehighest possible accuracy, because erroneous
inputs multiply thelevel of dimensioning or life expectancy errors.
The conditions during measurements are a frequent cause ofrelatively high
stray losses. The accuracy of a measuring methodcan be considerably
improved by introducing correction the error.
Keywords: electrical testing, electrical measurements, measurements condition, measurements errors, correction, electrical machines, diagnostics
- Type of paper
: Paper in proceedings
Title: POSSIBILITIES OF USAGE OF OPTICAL METHODS IN DETECTION OF
CHANGES DUE TO DETERIORATION OF INSULATING MATERIALS
- Authors:
- Bokulić, Darko
- Firinger, Vladimir (12014)
- Editors
- Firinger, Vladimir (12014)
Proceedings title: XX. Savjetovanje JUKO CIGRE; Elementi postrojenja: Izolacioni materijali
Language: hrvatski
Place: Neum, BH
Year: 1991
ISBN/ISSN: ž
Pages: from 49 to 52
Meeting: XX. Savjetovanje JUKO CIGRE
Held: from 04/21/91 to 04/26/91
Summary: Optical methods can provide information about the changes
incertain characteristics or conditions of insulating materialsthat cannot
be detected or measured by means of existingelectrical, chemical and
mechanical test methods.
A survey of degradation changes that cah be tested by opticalmethods in
insulating materials and systems of electricalmachines has been presented
in this paper. A survey of testmethods which could be used for detecting
and measuring thesechanges has also been given.
Keywords: insulating materials, insulating systems, degradation, diagnostics, testing, measuring, optical methods, laser, interferometry, holograf interferometry
- Type of paper
: Paper in proceedings
Title: OPERATING PROBLEMS IN MONITORING AND MAINTENANCE OF
ASCAREL-FILLED TRANSFORMATORS
- Authors:
- Čabrajac, Sonja (7516)
- Editors
- Fiala, Marija
- Kovađ, Irena
Proceedings title: Ekološke opasnosti kod eksploatacije energetskih transformatora i kondenzatora
Language: hrvatski
Place: Stubiđke Toplice, Hrvatska
Year: 1991
Pages: from 25 to 29
Meeting: Ekološke opasnosti kod eksploatacije energetskih transformatora i kondenzatora izoliranih askarelom
Held: from 10/09/91 to 10/10/91
- Type of paper
: Paper in proceedings
Title: CONTRIBUTION TO THE SOLUTION OF THE PROBLEM OF THE
SUBSTITUTION OF ASCARELS
- Authors:
- Čabrajac, Sonja (7516)
- Strineka, Ksenija
- Editors
- Firinger, Vladimir (12014)
Proceedings title: XX. Savjetovanje JUKO CIGRE: Elementi postrojenja;Izolacioni materijali
Language: hrvatski
Place: Neum, BH
Year: 1991
Pages: from 69 to 74
Meeting: XX. Savjetovanje JUKO CIGRE
Held: from 04/22/91 to 04/26/91
Summary: In spite of the lengtime efforts to find the lasting
solution tothe problem of the substitution of an ascarels, there is still
agreat number of transformers and capacitors exploited which arefilled with
ascarels that require maintenance under specialcontrol.
As it is noticeable from the different world solution that havebeen shown
here, a part of the problem is connected with theproblem of the
substitution of ascarels from transformers byanother insulation liquid,
while the second part of the problemrelates to storing and the destruction
of ascarels.
Some of the possible solutions of this problem were consideredand reported.
Keywords: transformers, electrical capacitors, dielectrical liquids, ascarels, maintenance
- Type of paper
: Paper in proceedings
Title: THE IMPROVEMENT OF ACCURACY OF BREAKDOWN VOLTAGE
DETERMINATION BY CORRECTION OF TEST DURATION INFLUENCE
- Authors:
- Firinger, Vladimir (12014)
- Editors
- Srb, Neven
Proceedings title: Zbornik radova: 3. Međunarodni Simpozij o novim tehnologijama: Tem.podr.:01-07
Language: hrvatski
Place: Opatija
Year: 1991
ISBN/ISSN: 86-81997-01-7
Pages: from 43 to 50
Meeting: 3. Međunarodni simpozij o novim tehnologijama SONT
Held: from 10/15/91 to 10/17/91
Summary: Although the breakdown voltage test is almost the oldest
kind ofelectric test of insulating materials, it has, as a
prescriptedmethod, certain insufficiently defined test conditions, which
maybecome the source of rather large measuring errors or evenillogical
representation of the measured property in relation tothe physical state of
the material.
In computation of the design of large and the largest machines,and in
diagnostics, the highest possible accuracy of input datais necessery. An
example of systematic error in breakdown voltagemeasurement due to
different test durations and the possibilitiesof its correction are
presanted in this paper.
Keywords: insulating materials, insulating systems, electrical measurements, breakdown voltage, measurements errors, correction, diagnostics
- Type of paper
: Paper in proceedings
Title: TESTING OF INSULATING OILS IN NON-REGULAR CONDITION
- Authors:
- Čabrajac, Sonja (7516)
- Hadži-Skerlev, Anđela (159894)
- Editors
- Cvetković, Zorko
Proceedings title: Obnova i izgradnja elektroenergetskog sistema R. Hrvatske: Diskusije
Language: hrvatski
Place: Zagreb
Year: 1992
Pages: from 1 to 3
Meeting: Obnova i izgradnja elektroenergetskog sistema Republike Hrvatske
Held: from 05/26/92 to 05/27/92
- Type of paper
: Paper in proceedings
Title: LIFE EXTENSION OF POWER TRANSFORMER INSULATING SYSTEM
- Authors:
- Mikulecky, Antun
- Godec, Zdenko
- Čabrajac, Sonja (7516)
- Editors
- Cvetković, Zorko
Proceedings title: Obnova i izgradnja elektroenergetskog sistema R. Hrvatske, Diskusije
Language: hrvatski
Place: Zagreb
Year: 1992
Pages: from 1 to 3
Meeting: Obnova i izgradnja elektroenergetskog sistema Republike Hrvatske
Held: from 05/26/92 to 05/27/92
- Type of paper
: Paper in proceedings
Title: APPLICATION OF A DIAGNOSTIC METHOD ADAPTED FOR ELECTRICAL
MACHINES WITH DAMAGED WINDINGS
- Authors:
- Firinger, Vladimir (12014)
- Editors
- Cvetković, Zorko
Proceedings title: Obnova i izgradnja elektroenergetskog sistema R. Hrvatske, Diskusije
Language: hrvatski
Place: Zagreb
Year: 1992
Pages: from 1 to 4
Meeting: Obnova i izgradnja elektroenergetskog sistema Republike Hrvatske
Held: from 05/26/92 to 05/27/92
- Type of paper
: Paper in proceedings
Title: CLASSIFICATION OF LIQUID DIELECTRICS
- Authors:
- Čabrajac, Sonja (7516)
- Editors
- Konđan-Gradnik, Maja
Proceedings title: SLOKO CIGRE: prva slovenska konferenca
Language: hrvatski
Place: Ljubljana, Slovenija
Year: 1993
ISBN/ISSN: 961-90028-0-6
Pages: from 85 to 90
Meeting: SLOKO CIGRE: prva slovenska konferenca
Held: from 05/25/93 to 05/26/93
Summary: Practical application of liquid dielectrics presupposes
goodknowledge of various material properties in order to be able toensure
reliable manipulation, uses, storage and finally harmlessdisposal and
destruction of the wasteinsulating liquids.
The knowledge and application of classification systems and ofthe
characterization make it possible to classify the materialsin groups and
sub-groups according to various criteria that areimportant for individual
stages of application.
Keywords: classification, liquid dielectrics, insulating oils
- Type of paper
: Paper in proceedings
Title: SYSTEMATIC QUALITY CHECKING SYSTEM OF RESTORED INSULATORS
- Authors:
- Firinger, Vladimir (12014)
- Polak, Josip (68325)
- Mesar, "eljko
- Editors
- Polak, Josip (68325)
Proceedings title: Prvo savjetovanje Hrvatskog komiteta CIGRE: I. sekcija-Elementi postrojenja
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 353 to 363
Meeting: Prvo savjetovanje Hrvatskog komiteta CIGRE
Held: from 10/10/93 to 10/13/93
Summary: The appearance of several different technologies of
restorationand final processing of insulators has imposed the need to
checkthe appropriateness of the applied technique and the attainedquality.
In this sense a system of checkig the quality and reliability offinished
insulators has been developed.
Keywords: High voltage, insulators, restoring, checking, quality. reliability
- Type of paper
: Paper in proceedings
Title: CLASSIFICATION OF LIQUID DIELECTRICS BY DIFFERENT
CRITERION
- Authors:
- Čabrajac, Sonja (7516)
- Hadži-Skerlev, Anđela (159894)
- Strineka, Ksenija
- Editors
- Polak, Josip (68325)
Proceedings title: Prvo savjetovanje Hrvatskog komiteta CIGRE: I. sekcija-Elementi postrojenja
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 365 to 374
Meeting: Prvo savjetovanje Hrvatskog komiteta CIGRE
Held: from 10/10/93 to 10/13/93
Summary: Practical application of liquid dielectrics pressuposes
goodknowledge of various material properties in order to be able toensure
reliable manipulation, uses,storage and finally harmlessdisposal and
destruction of the insulating liquids waste.
Classification systems and methods of the characterization makeit possible
to classify the materials in groups and sub-groupsaccording to various
criteria that are important for individualstages of manipulation and
application.
Keywords: classification, liquid dielectrics
- Type of paper
: Paper in proceedings
Title: THE AGE OF TRANSFORMERS IN THE POWER SUPPLY SYSTEM OF
CROATIA
- Authors:
- Mikulecky, Antun
- Čabrajac, Sonja (7516)
- Gongola, Želimir
- Krota, Branko
- Mičuga, Josip
- Modrić, Željko
- Editors
- Godec, Zdenko
Proceedings title: Prvo savjetovanje Hrvatskog komiteta CIGRE- I.sekcija-Elementi postrojenja
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 167 to 176
Meeting: Prvo savjetovanje Hrvatskog komiteta CIGRE
Held: from 10/10/93 to 10/13/93
Summary: The reliability of service of comparatively old
transformers canbe ensured by measures for prolonging their life or by
lifeextension. On the basis of a poll, the age of power
transformers,highest system voltage from 123 kV to 420 kV, has been
analyzed.The results can be helpful in realizing the priorities
indetermination of the degree of transformer aging and their lifeextension.
Because of rather numerous old transformers, the lifeextension should be
performed systematically, and the authorsgive their proposal of the
sequence of life extension activities.
Keywords: power transformer, age, life extension
- Type of paper
: Paper in proceedings
Title: LIFE EXTENSION OF THE POWER TRANSFORMERS
- Authors:
- Mikulecky, Antun
- Čabrajac, Sonja (7516)
- Editors
- Godec, Zdenko
Proceedings title: Prvo savjetovanje Hrvatskog komiteta CIGRE: I.sekcija-Elementi postrojenja
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 177 to 186
Meeting: Prvo savjetovanje Hrvatskog komiteta CIGRE
Held: from 10/10/93 to 10/13/93
Summary: The portion of comparatively old components in electric
powersystems is rather high. The more developed a system, the largertheir
portion. Recently great attention has been given to theanalysis of the
aging of old components and to investigation ofpossibilities to extend
their life. Thus is it tried to reducethe costs of replacement of old
components with new ones, and toincrease the reliability of service of the
components. Theobjective of the paper is to present the results of the
foreignand of our investigations on power transformers. The mechanismsof
transformer aging and the methods for life extension aredescribed.
Procedures and criteria for diagnosis for reneval areproposed.
Keywords: power transformer, ageing, life extension
- Type of paper
: Paper in proceedings
Title: MODEL FOR INVESTIGATION OF TRANSFORMER INSULATION AGEING
- Authors:
- Mikulecky, Antun
- Čabrajac, Sonja (7516)
- Godec, Zdenko
- Editors
- Cvetković, Zorko
Proceedings title: II. Savj. Hrv. kom. međunar.konfer. za vel. elektr. sist.,Sek.1-Oprema
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 953-6408-00-7
Pages: from 121 to 127
Meeting: Drugo savjetovanje Hrvatskog komiteta međunarodne konferencije za velike električne sisteme
Held: from 05/14/95 to 05/18/95
Summary: Remaining life of the transformer insulation can be
determined by using special diagnostics methods. A model for investigation
of oil immersed transformers insulation ageing is described in this paper.
This model enables choosing and inspection of insulation ageing relevant
parameters as well as application of diagnostics methods for determination
ofinsulation ageing. The objective of the investigation is to define a
correlation between direct and indirect diagnostics methods for
determination of transformers insulation ageing state and also more
reliable assessment of transformers insulation remaining life.
Keywords: power transformer, diagnostics, insulation, ageing, model
- Type of paper
: Paper in proceedings
Title: RESULTS OF ELECTRIC PAPER AGEING TESTS OF TRANSFORMER IN
SERVICE
- Authors:
- Čabrajac, Sonja (7516)
- Mikulecky, Antun
- Podobnik, Vladimir
- Musulin, Božena
- Editors
- Cvetković, Zorko
Proceedings title: II. Savj. Hrvat. komit. međun. konf. za vel. elektr. sist.,Sekc. I- Oprema
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 953-6408-01-5
Pages: from 113 to 119
Meeting: Drugo savjetovanje Hrvatskog komiteta međunarodne konferencije za velike električne sisteme
Held: from 05/14/95 to 05/18/95
Summary: For a number of years the ageing of electric paper has been
tested by means of measurements of the average viscosimetric degree of
polymerisation of transformers paper. The results of tests made so far have
provided insight into the ageing of transformers in the Croatian power
system. The paper explains the significance of the determination of paper
ageing from the standpoints of transformer reliability. It also gives
systematised results and some comparison with data found in the literature.
Some recommendations are given for future activities.
Keywords: power transformer, testing, ageing, paper polymerisation degree
- Type of paper
: Paper in proceedings
Title: CRITERIA FOR EVALUATION OF MINERAL INSULATING OIL QUALITY
- Authors:
- Čabrajac, Sonja (7516)
- Musulin, Božena
- Hadži-Skerlev, Anđela (159894)
- Jaman, Nikola
- Editors
- Cvetković, Zorko
Proceedings title: II. Savj. Hrvat. komit. međun. konfer. za vel. elektr. sist., Sekc. I - Oprema
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 953-6408-01-5
Pages: from 175 to 181
Meeting: Drugo savjetovanje Hrvatskog komiteta međunarodne konferencije za velike električne sisteme
Held: from 05/14/95 to 05/18/95
Summary: Quality of new mineral insulating oils for transformers
depends on stability of oil properties in service. Oxidation stability
laboratory tests with new oils enable evaluation of oil quality and
lifetime prediction.
Lifetime of defined oil quality in operation conditions of transformers
depends on configuration of insulating system and operation under
condition. Approval of quality of oils is given through monitoring of
behaviour of oils under exploatation condition.
Keywords: mineral insulating oils for transformers, testing, quality, criteria
- Type of paper
: Paper in proceedings
Title: DIAGNOSTICS OF STATE OF INSULATING SYSTEMS OF HIGH-VOLTAGE
ELECTRICAL ROTATING MACHINES
- Authors:
- Polak, Josip (68325)
- Antolić, Nada
- Editors
- Cvetković, Zorko
Proceedings title: II.Savj. Hrvat. komit. međun. konfer. za vel. elektr. sist., Sekc. I.-Oprema
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 953-6408-01-5
Pages: from 213 to 216
Meeting: Drugo savjetovanje Hrvatskog komiteta međunarodne konferencije za velike električne sisteme
Held: from 05/14/95 to 05/18/95
Summary: The importance of diagnostics of insulating system is
presented from the standpoint that its life is essential for reliable
operation of high-voltage electrical rotating machines. Dielectric
characteristics of insulating systems that are determined by test and
measurements are also briefly presented, and the conclusion is given with
respect to reliable estimation of life of insulating systems based on
diagnostics of its state.
Keywords: insulating system, life, diagnostic, insulating resistance, dissipation factor, partial discarges
- Type of paper
: Paper in proceedings
Title: THE INFLUENCE OF MOTORS OVERLOAD ON MATERIAL DEGRADATION
IN INSULATING SYSTEM
- Authors:
- Firinger, Vladimir (12014)
- Editors
- Srb, Neven
Proceedings title: Proceedings of the 8th International Conference on Electrical Drives and Power E
Language: engleski
Year: 1994
ISBN/ISSN: 953-6037-04-0
Pages: from 22 to 25
Meeting: 8th International Conference on Elecrical Drives and Power Elektronics
Held: from 09/12/94 to 09/14/94
Summary: It is demonstrated how voltage and thermal loads influence
the rate of material degradation by using the characteristic constant of
materials, by means of which is possible to determine the depedence of
material degradation on load time.Such knowledge is nessery when choosing
the material and dimensions, as well as in diagnostics of real insulating
system, since insulating materials and systems are declared only with
regard to long-time endurance and only for fixed time and limit of
degradation of the proposed property.
Keywords: insulating materials, insulating systems, electrical motors, electrical drives, overload
- Type of paper
: Paper in proceedings
Title: EFFECTS OF VOLTAGE AND HEAT OVERLOAD ON ACCELERATION OF
INSULATING MATERIAL DEGRADATION
- Authors:
- Firinger, Vladimir (12014)
Proceedings title: 7th International electrical insulation conference BEAMA-INSUCON
Language: engleski
Place: London, Engleska
Year: 1994
Meeting: 7th International electrical insulation conference BEAMA-INSUCON
Held: from 05/23/94 to 05/25/94
Summary: Consideration based on the general form of equatation of
material degradation are made in order to compare the effects of specific
voltage and thermal degradations and overloads on acceleration of material
degradation. Evaluation of ageing is necessary for diagnostics and design
of insulating systems.
In evaluation of insulating materials and sytems there are limits such as
temperatures of thermal classes, temperature indices and profiles, which in
a defined time give a defined degree of degradation. In practice there are
frequent and often necessary deviations from the specified stress, and
there are quite different stress times and limits of allowable degradation.
Keywords: Insulating materials, insulating systems, degradations, ageing, overload
- Type of paper
: Ph.D.
Title: INVESTIGATION OF SOLID INSULATING MATERIALS WITH RESPECT
TO THE ACCURACY OF DETERMINATION OF THEIR RESISTIVITY TO BREAKDOWN
Faculty: Elektrotehnički fakultet Zagreb
Author: FIRINGER VLADIMIR
Date of defense: 03/27/92
Language: hrvatski
Number of pages: 108
Summary: Although the breakdown voltage test is the oldest of
electrictests of insulating materials, it, as a prescribed method, stillhas
some insufficiently defined points, which cause comparativlylarge measuring
errors and illogical expressions of measuredproperties in relation to the
physical state of the material. Onthe basis of an analysis of causes of
measuring errors and theirconsequences, especially by diagnostic testing,
the following isproposed for using the prescribed method using:
-narrower frequency range
-better sinusoidal form of the voltage source
-reversion of measuring ranges
-revision of voltage increase rate
-revision of test duration, and
-introduction of correction errors due to different testdurations
Keywords: electrical testing, measuring technology, breakdown voltage, measuring errors, correction, insulating materials, insulating systems, technical diagnostics
