insulating materials: analyses and their application for
TRANSCRIPT
TRANSFORM Partner
Dr. Jürgen Schübel
Messko GmbH
Insulating Materials: Analyses and their application for transformer and tap changer monitoring
06.06.2013 Dr. Jürgen Schübel, Messko GmbH Page 2
Personal Introduction
Name Dr. Jürgen Schübel
Age 49
Studies
1983 – 1989
1989 - 1991
Chemistry at Ludwig-Maximilians-
University, Munich
PhD – Thesis at Max-Planck-
Institute for Polymer Research,
Mainz
1991 - 2011 Work at a Mineral Oil Company,
Refining
Since 2011 Head of Basic Development, Oil
Laboratory and Diagnostics at
Messko Instruments, Oberursel
Email [email protected]
1. Oil and paper degradation processes
2. Analyses for monitoring these degradation processes
3. Data interpretation for transformers and tap changers
4. Online analysis systems
5. Conclusion – Integrated Control System
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Agenda
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Degradation processes – Mineral Oil
C C
C C
C C
C C
corr
osiv
e p
rocess
degra
dation p
rocess
+
O-O . C
C C
+
OH
CHO
O
C C
C
C C
C
C C
C
COOH C C
C
+ COO - H+
C C
C Corrosion
+
C C
C C
C
H2, CH4, C2H2, C2H4, C2H6 C
C C
C C
C C
C C
C C
Oil Sludge
+
Ch
em
ica
l ca
taly
tic p
roce
ss
Energ
y „
inp
ut“
pro
ce
ss
Chemical high reactive
intermediate products
Acid value
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Degradation processes
reduction of oil quality (carbon + ketones)
fast reduction of depolymerisation value (DP)
chemical reaction water + acid
reduction of oil quality (water + gases)
carbonisation of paper
oxidative / hydrolytic depolymerisation
low activation energy This aging process you will also find
in deenergized transformers in the presence
of oxygen and moisture
thermal depolymerisation
high activation energy
chemical reaction
chemical reaction
oil dissolved gases
alcohols, acids
oil sludge
cellulose carbon monoxide CO
carbon dioxide CO2
dissolved glucose rings
oxidation water
acids
ketones
(carbon bounded molecules)
hydrolysis dissolved glucose molecules
Oxidative Hydrolysis water + acids + oxygen Pyrolysis temperature
Ambient 118°C 150°C 100°C 105°C 75°C - 98°C
water water
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Analyses methods
DGA
Color Index
Interfacial Tension
Moisture
Breakdown Voltage
Solids
Neutralization number / Aciditiy
Impurities
Furane analysis
Degree of polymerisation (DP)
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Data Interpretation – Chemical and Electrical Parameters
Propert y Categor y a Recommended
action limits
Good Fair
Poor
Recommended action b, c Notes
Colour and appearance All Clear and Dark
and/or without visible
turbid
contamination
As dictated by other tests Dark colour is a symptom of chemical
contamination or ageing.
Turbidity is a symptom of high water content
Breakdown voltage (kV) O, A, D > 60 50 to 60 <
50
Good: Continue normal sampling.
Fair: More frequent sampling. Check other
parameters, e.g. water, particle content and
perhaps DDF/resistivity
and acidity.
Poor: Recondition the oil (see 11.2) or,
alternatively, if more economical
because other tests indicate severe ageing,
replace (see Clause 12) or reclaim (see
11.3) the oil combined
with subsequent drying procedures
B, E > 50 40 to 50 <
40
C > 40 30 to 40 <
30
F < 30 kV for OLTC in star-point
appl ication.
< 40 kV for OLTC in delta
or l ine-end appl ication
G < 30
W ater content (mg/kg at
transformer operating
temperature)
O, A < 15 15 to 20 >
20
Good: Continue normal sampling.
Fair: More frequent sampling. Check other
parameters e.g. breakdown
voltage, particle content and perhaps
DDF/resistivity and acidity.
Poor: Check source of water,
recondition the oil (see 11.2) or,
alternatively, if more economical
because other tests indicate severe ageing,
replace (see Clause 12) or reclaim (see
11.3) the oil combined
with subsequent drying procedures,
although regard should be taken of the quantity
of water that will sti l l be
retained in the solid insulation
The values of water content shall be always
regarded together with the values for breakdown voltage. In
case of a suspicion of a moisture
problem, sampling at different equipment
temperatures is recommended.
In case of switching equipment without paper
insulation (Category F), the values of breakdown voltage are
of overriding importance.
The listed l imit values represent 90 % statistical values and
are valid for transformer operating
temperatures. The equilibrium between sol id and liquid insulation under 40 °C is not rel iable and for heavy loaded
transformers with oil temperature
over 70 °C an implementation of the correction procedure
described in Annex A may be useful.
B, D < 20 20 to 30 >
30
C, E < 30 30 to 40 >
40
F Action
necessity > 40
G Not a routine test
Table 5 – Application and interpretation of tests (1 of 4), IEC 60422 - 2013
Data Interpretation – DGA / Transformer
Key gas ratio acc. to Rogers
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Key gas ratios according to
Rogers
Principal gases
Key gas ratio acc. to Doernenburg
Source: IEEE C57.104
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Data Interpretation – DGA / Transformer
Duval Triangle acc. to DIN EN 60599
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Data Interpretation – DGA / Tap Changer
generated by CIGRE Working group D1.32 (disbanded); see Final Report: CIGRE Brochure 443
Examples:
– GE LRT-72, McGrawEdison 550, Westinghouse UTT, UTS :
– Reinhausen OILTAP® M, ABB UCG :
– Reinhausen VACUTAP® RMV-II, GE LRT-200..700 :
– Reinhausen VACUTAP® VR series, VACUTAP® VM :
AXC
ARS
VXC
VRS
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Data Interpretation – DGA / Tap Changer
R
VAC
Classification:
VRS
H2 C2H2 CH4 C2H6 C2H4 CO
H2 C2H2 CH4 C2H6 C2H4 CO
bar
rier
bo
ard
transformer tank selector tank
Heating Pattern <300°C
Sparking Pattern
Very low absolute ppm levels
Temperature
mechanical thermometers
bellow type
type with Bourdon spring
Moisture
systems based on capacity measurement
DGA
gaschromatographic systems (5 to 9 gases)
IR spectroscopic systems (3 to 9 gases)
photoacoustic systems (up to 9 gases)
systems based on semiconductive metal oxides sensors (1 to 2 gases)
systems based on fuel cells (1 gas or sum of gases)
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Online Analysis Systems
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Integrated Control System - Summary
Integrated Control System
Laboratory Analysis
• Break down voltage
• Interfacial tension
• Furane analysis
• …
Online Analysis
• DGA (2 to 5 gases)
• Moisture
• Temperature
with easy-to-use and
robust systems
Specific Knowledge
•Transformer
•Tap Changer
• Chemistry
• Physics
• Data evaluation
Laboratory
Online
Knowledge
• Integration of laboratory and online data together with knowledge
leads to enhanced operational safety and projectable maintenance
in a short period of time
• Together with additional qualification of the staff cost reductions
and longer life cylce times can be expected in a medium period of
time
• Collecting many data of normal and failure operation leads to big
data basis generating increased knowledge, better analyses and
data interpretation and enhancement of standards.
Dr. Albert Hauser founds the company
Concentration on radiator thermometers for motor vehicles
First thermometer with bourdon tube
The brand was born
Main focus on industry/plant engineering
First thermometer of Compact Series
Start of Oil Level Indicator Series
Messko moves to new location
Becomes the subsidiary of Maschinenfabrik Reinhausen
Market introduction MESSKO® MPreC© and MESSKO® MTraB©
New Messko works in Oberursel
New Flow Indicator MESSKO® MFloC® will be launched
100th anniversary
Introduction MESSKO® MSafe® Buchholz Relay and MESSKO ® MLog®
06.06.2013 Page 14
Messko Instruments
Foundation of Messko Nordic in Sweden
1911
1922
1932
1935
1954
1960
1975
1989
1999
2003
2008
2010
2011
2012
Dr. Jürgen Schübel, Messko GmbH
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Thank you for your attention !
1. M. Duval: “The Duval triangle for Load Tap Changers, Non-Mineral Oils and Low temperature Faults in Transformers“, IEEE Electrical
Insulation Magazine, 0883-7554/07, 2008
2. P.Birkbeck et.al.: “Electric Arc Furnace Tap Changers – A Multifaceted Approach to Improving the Reliability and Performance of EAF On-
Load TapChangers“, AISTech Pittsburgh, 2010
3. Final Report of CIGRE WG D1.32: CIGRE Brochure No. 443, Dec 2010
4. IEEE PC57.139: “Draft Guide for Dissolved Gas Analysis in Transformer Load Tap Changers”,
D16, Oct 2010
Literature
T H E P O W E R B E H I N D P O W E R .
www.reinhausen.com