Scion Instruments solution on transformer oil gas analyzer by PT. Saranalab Mandiri Analitika

1. .
New SCION GC’s
Providing Performance and Flexibility

2. .
Tranformer Oil Gas Analyzer (TOGA)

3. .
TOGA Analyzer Guidance
ASTM D 3612 Standard Test Method for Analysis of
Gases Dissolved in Electrical Insulating Oil by Gas
Chromatography
IEEE C57.104 IEEE Guide for the Interpretation of
Gases Generated in Oil-Immersed Transformers

4. .
ASTM 3612
Method A - Dissolved gases are extracted from a sample of oil by introduction of the oil sample
into a pre-evacuated known volume. The evolved gases are compressed to atmospheric pressure
and the total volume measured
Method B - Dissolved gases are extracted from a sample of oil by sparging the oil with the
carrier gas on a stripper column containing a high surface area bead
Method C - Method C consists of bringing an oil sample in contact with a gas phase (headspace)
in a closed vessel purged with argon. The dissolved gases contained in the oil are then
equilibrated in the two phases in contact under controlled conditions (in accordance with
Henry’s law). At equilibrium, the headspace is overpressurized with argon and then the content
of a loop is filled by the depressurization of the headspace against the ambient atmospheric
pressure. The gases contained in the loop are then introduced into a gas chromatograph

5. .
Scion Instruments TOGA System

6. .

7. .
Fill Mode

8. .
Inject Mode

9. .
Backflush
Mode

10. .
Scion Instruments TOGA System
TCD Channel - MS Column
Permanent Gasses

11. .
Scion Instruments TOGA System
FID Channel - Plot Column
CO, CO2, C2s, C3s

12. .
Maintenance of TOGA System
a. Daily Iso-octane flush (at the end of the day), and Purged with gases
b. Overnight, park the oven at low temperature:30°C
c. Make a blank run at the start of the day, or a series of analyses
d. A regular bake-out at 150°C for at least one hour is recommended. After successive analyses,
heavier components such as C4’s and C5’s may accumulate on the FID channel.
e. Decreasing retention times of the Molecular Sieve column (H2, O2 & N2), this column needs
reconditioning. Conditioning needs to be done in a different oven under nitrogen or helium at a
temperature of 300 °C overnight. Sometimes conditioning overnight of the Molsieve columns in
the GC oven at 180 °C will be sufficient. Check the status of the humidity filter in case of
conditioning is needed.
f. In case of of the BR-U PLOT column (CO, CO2, C2s, C3s), conditioning in the GC oven can be
done. However it is mandatory to disconnect the column from the methaniser.

13. .
Interpretation of TOGA Result
Gas Formation
Thermal Disturbance
Electrical Disturbance
Decomposition
Cellulosic
(CO, CO2,
H2, CH4)
Oil (H2, C2s,
C3s)

14. .
Interpretation of TOGA Result

15. .
Interpretation of TOGA Result
Establishing Data
Routine basis
Daily / Weekly after a Start Up --> Monthly or Longer
Generator Step Up (GSU) --> 4 - 6 / Year
> 138 KV --> 2/ year
765 kV --> monthly

16. .
Interpretation of TOGA Result
Faults
Thermal
Partial Discharge
Arcing

17. .
Interpretation of TOGA Result
Only 42%
KGM is
correct

18. .
Interpretation of TOGA Result
Doernenburg Ratio Method (DRM)
This method [34], [35] uses the ratio of gas concentrations to indicate fault types. Predefned limits
for the CH4/H2, C2H2/C2H4, C2H2/CH4, and C2H6/C2H2 ratios are used to interpret the DGA results
(Table 2) [34]. DRM diagnosis cannot be applied unless the concentration of at least one of the key
gases (H2, C2H4, CH4, and C2H2) exceeds twice the relevant L1 concentration (Table 3) and the
concentration of at least one of the two gases appearing in any one of the four ratios exceeds the
relevant L1 concentration [8]. The proposed fault diagnosis is based on the ranges of the four ratios
shown in Table 2

19. .
Interpretation of TOGA Result
Rogers Ratio Method (RRM)
The RRM originally used four concentration ratios, namely
C2H6/CH4, C2H2/C2H4, CH4/H2, and C2H4/C2H6, leading to 12
proposed diagnoses [9]. However, the condition C2H6/CH4 <1
held for 10 of the 12 suggested diagnoses, i.e., the ratio C2H6/
CH4 was of little diagnostic value [32], [35]. This ratio was
therefore omitted in the revised IEEE Standard C57.104-1991
[8], and the original 12 suggested diagnoses were replaced by
six (including the normal state), as shown in Table 4 [34].
However, inconsistencies have been reported [1], [7], the success
rate for correct fault type identifcation being 58.9% [7]

20. .
Interpretation of TOGA Result
IEC Ratio Method (IRM)
This method uses the same three ratios as the revised RRM but
suggests different ratio ranges and interpretations, as shown in
Table 5 [36]. A new gas ratio has been introduced, namely C2H2/
H2 to detect possible contamination from on-load tap-changer
compartments [38]. Another improvement is 3-D graphical
representation of ratio ranges, which yields more reliable diagnoses,
and diagnoses of faults associated with ratios outside the
ranges quoted in Table 5 [1].

21. .
Interpretation of TOGA Result
Duval Triangle Method (DTM)
This method was developed from an existing IEC 60599 Ratio method and
IEC TC10 databases [36]. It interprets DGA datausing graphical
presentation [39], [40]. It uses the concentrations of CH4, C2H2, and C2H4,
which are plotted along three sides of a triangle [39], as shown in Figure 9.
Within the triangle there are seven fault zones, covering partial discharge,
thermal faults at various temperatures, and electrical arcing. According to
[7], [35], and [37], the DTM provides more accurate and consistent
diagnoses than the other ratio methods. However, careless
implementation leads to incorrect diagnoses [40]. Moreover, since the
triangle does not include the fault-free condition, the method cannot be
used to detect incipient faults

22. .
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