INFOKUM
Volume 13.
Number 06, 2025.
DOI 10.
58471/infokum.
ESSN 2722-4635 (Onlin.
https://infor.
org/index.
php/infokum Dissolved Gas Analysis (DGA) Testing Analysis on 150kv Power Transformers Muhammad Rivai1.
Muhammad Erpandi Dalimunthe2.
Dino Erivianto3 Electrical Engineering Study Program.
Faculty of Science And Technology.
Pembangunan Panca Budi University.
Jln.
Jend.
Gatot Subroto Km.
4,5 Medan Provinsi Sumatera Utara Article Info Keywords:
Dissolved Gas Analysis (DGA) power transformer insulating oil This is an open access article under the CC BY-NClicense ABSTRACT This research used a laboratory experimental method with a quantitative approach.
The aim was to measure and analyze the dissolved gas content in power transformer oil and to explain the measurement results based on the Ie C57.
104-2008 standard and PT PLN's Decree No.
0520 K/DIR/2014.
The research objects were Power Transformers 1 and 2 of the 150 kV Titi Kuning Substation on Jalan Suka Tirta No.
Medan.
North Sumatra.
The analysis used two methods to determine the condition of this transformer: TDCG and Key Gases.
The first method is to measure the contents of Hydrogen (H.
Acetylene (CH.
Ethylene(CH.
Ethane (CH.
Methane.
Carbon monoxide (CO), and Carbon dioxide (CO.
The second method involves summing the values of Gas Chromatography Method (TDCG) for Dissolved Gas Analysis (DGA) analysis, and the third method is a key gas method for determining the type of damage or abnormalities in a transformer.
Corresponding Author:
Muhammad Rivai Electrical Engineering Study Program.
Faculty of Science And Technology.
Pembangunan Panca Budi University.
Jln.
Jend.
Gatot Subroto Km.
4,5 Medan Provinsi Sumatera Utara mhdrivai20@gmail.
INTRODUCTION
PT PLN (Perser.
is a company that provides electricity for the public interest in Indonesia.
In line with one of PLN's missions, which is to operate the electricity business and other related fields, oriented towards customer satisfaction, it is crucial for PLN (Perser.
to improve the reliability of electricity distribution.
PT PLN (Perser.
has several implementing units, each with its own roles and responsibilities.
Some well-known implementing units are the transmission implementing unit, responsible for the distribution of high and extra-high voltage electricity, and the customer service implementing unit, responsible for the distribution of medium and low voltage electricity.
To improve the reliability of electricity distribution.
PT PLN (Perser.
needs to conduct maintenance activities.
Maintenance is a business activity that aims to achieve organizational goals, implement strategies, and implement organizational work plans.
Maintenance in PLN's transmission units includes preventive and corrective maintenance Preventive maintenance is a routine, scheduled maintenance strategy to ensure equipment or assets continue to function according to their intended purpose.
The primary Dissolved Gas Analysis (DGA) Testing Analysis on 150kv Power TransformersAe Muhammad Rivai et.
1901 | P a g e
INFOKUM
Volume 13.
Number 06, 2025.
DOI 10.
58471/infokum.
ESSN 2722-4635 (Onlin.
https://infor.
org/index.
php/infokum goal of preventive maintenance is to maximize the lifespan of equipment or assets and prevent malfunctions that could lead to power outages.
Corrective maintenance is performed to repair damaged equipment or assets, with the aim of restoring them.
Power transformers are the most crucial component in transmitting electrical power.
Power transformers function to change voltage, either by increasing or decreasing it.
The condition of power transformers is crucial, as they are relatively expensive and spare transformers are scarce.
Therefore, regular monitoring of the condition of existing power transformers is essential.
Power transformers contain insulating oil.
This insulating oil protects the transformer from electrical failures within the transformer itself.
To determine whether there are any abnormalities in the transformer, the impact of the abnormality can be determined by conducting a Dissolved Gas Analysis (DGA) test.
This test allows companies to take immediate action on the transformer.
Related Research The two main causes of gas formation in operating transformers are thermal and electrical disturbances.
Conductor losses due to loading produce gas from the thermal decomposition of oil and associated solid insulation.
Gas is also produced from the decomposition of oil and insulation exposed to arc temperatures.
Generally, decomposition gas is formed primarily by processes in which the surface of a material contains high-energy charged ions.
Mineral insulating oil is composed of many molecules with the chemical groups CH3.
CH2, and CH3 held together by carbon molecular bonds.
The gases detected in Dissolved Gas Analysis (DGA) tests are Hydrogen (H.
Acetylene (CH.
Ethylene (CH.
Ethane (CH.
Methane (CH.
Carbon monoxide (CO), and Carbon dioxide (CO.
DGA Test Data Interpretation Method Based on the test results, possible abnormalities can be investigated using several methods according to the Ie C57-104.
2008 standard and PT PLN Decree No.
K/DIR/2014, namely:
TDCG (Total Dissolved Combustible Ga.
Method When an abnormality occurs in a transformer, there is a sudden increase in the dissolved gas content in the transformer oil.
The TDCG method calculates the total amount of flammable gases dissolved in the transformer oil.
CO2 is not a flammable gas and is therefore not included in the TDCG results.
Table 1.
Main Dissolved Gas Concentration Limits [Ul/L (Pp.
Kondisi
>1800
CH4
>1000
>1400
CO2
C2H4
C2H6
C2H2
TDCG
>10000
>200
>150
>35
>4630
Condition 1: A TDCG below this level indicates that the transformer is operating Condition 2: A TDCG within this range indicates a higher-than-normal level of Dissolved Gas Analysis (DGA) Testing Analysis on 150kv Power TransformersAe Muhammad Rivai et.
1902 | P a g e
INFOKUM
Volume 13.
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Any flammable gas exceeding this level should prompt additional Condition 3: A TDCG within this range indicates a high level of decomposition.
Any flammable gas exceeding this level should prompt additional investigation.
Condition 4: A TDCG exceeding this value indicates excessive decomposition.
Continued operation could result in transformer failure.
Key Gas Method The Key Gas Method is defined by Ie C.
104-2008 as the gases formed in oilcooled transformers that can be used to qualitatively determine the type of failure that has occurred, based on the typical or predominant gas types formed at various temperatures.
Table 2.
Types Of Failure According To The Key Gases Method Gas Dominan Ethylene C2H4 Carbon Monoxide CO Hydrogen H2 Hydrogen and Acetylene H2.
C2H2 Jenis Fault Thermal mineral oil Thermal mineral oil and cellulose Electrical low energy partial discharge (PD) Electrical high energy .
Thermal mineral oil: Decomposition products include ethylene (C2H.
and methane (CH.
with small amounts of hydrogen (H.
and ethane (C2H.
Signs of acetylene (C2H.
may form if the fault is severe or if electrical contact occurs.
Figure 1.
Oil overheating Thermal mineral oil and cellulose: A small amount of carbon dioxide (CO) and carbon monoxide (CO.
is produced due to heating of cellulose.
Hydrocarbon gases, such as methane (CH.
and ethylene (C2H.
, are produced if the fault involves the oil structure.
Figure 2.
Excessive heat in paper Electrical low-energy partial discharge: A low-energy electrical discharge produces Dissolved Gas Analysis (DGA) Testing Analysis on 150kv Power TransformersAe Muhammad Rivai et.
1903 | P a g e
INFOKUM
Volume 13.
Number 06, 2025.
DOI 10.
58471/infokum.
ESSN 2722-4635 (Onlin.
https://infor.
org/index.
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and methane (CH.
with small amounts of ethane (C2H.
and ethylene (C2H.
Comparable amounts of carbon monoxide and carbon dioxide may be produced from the discharge in cellulose Figure 3.
Partial Discharge in oil Electrical high-energy .
: A small amount of hydrogen (H.
and acetylene (C2H.
are produced, along with some methane (CH.
and ethylene (C2H.
Carbon dioxide and carbon monoxide are always produced if the fault involves cellulose.
The oil may be carbonized.
Figure 4.
Arcing in oil
METHOD
This research used a laboratory experimental method with a quantitative approach.
The aim was to measure and analyze the dissolved gas content in power transformer oil and to explain the measurement results based on the Ie C57.
104-2008 standard and PT PLN's Decree No.
0520 K/DIR/2014.
This research was conducted at the 150 kV Titi Kuning Substation on Jalan Suka Tirta No.
Medan Johor.
Medan.
North Sumatra.
The research objects were Power Transformers 1 and 2 of the 150 kV Titi Kuning Substation.
The data in Table 3 shows the specifications of power transformers 1 and 2 of the 150 kV Titi Kuning Substation.
Table 3.
Transformer Specifications Information Trafo I Trafo II Manufacture PASTI B&D Year Of Manuf.
Standard
IEC 76
IEC 60076
Dissolved Gas Analysis (DGA) Testing Analysis on 150kv Power TransformersAe Muhammad Rivai et.
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INFOKUM
Volume 13.
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org/index.
php/infokum Rated Power
Cooling 60 MVA
ONAN/ONAF
70/100%
50 Hz
36/60 MVA
ONAN/ONAF
Frequency 50 Hz Phases Connection YNyn0 d YNyn0 d Symbol Max Altitude The Dissolved Gas Analysis (DGA) test used the Gas Chromatography method with a Morgan Schaffer Myrkoz MYR-011 Portable DGA tester to determine the levels of dissolved gases in power transformer oil.
Table 4 shows the data collected from the Dissolved Gas Analysis (DGA) test results for Power Transformer 1 at the 150 kV Titi Kuning Substation, and the oil sample testing was conducted on November 23, 2023.
Table 4.
Testing Results Of The Power Transformer Dga 1 At The Titi Kuning Substation Parameter Uji Konsentrasi .
Hydrogen H2 Methane CH4 Carbon monoxide CO Carbon dioxide CO2 Ethylene C2H4 Ethane C2H6 Acetylene C2H2 In Table 5, the data taken are the results of the Dissolved Gas Analysis (DGA) test from the Power Transformer 2 of the 150 kV Titi Kuning Substation and oil sample testing was carried out on November 23, 2023.
Table 5.
Testing Results Of Power Transformer Dga 2 Substation At Titi Kuning Parameter Uji Konsentrasi .
Hydrogen H2 Methane CH4 Carbon monoxide CO Carbon dioxide CO2 Ethylene C2H4 Ethane C2H6 Acetylene C2H2 The data in tables 4 and 5 are used as a reference for determining the condition of the transformer and as analysis material to determine the appropriate steps for the transformer referring to the IEEC 57.
104-2008 standard and KEPDIR No.
0520 K/DIR/2014.
Dissolved Gas Analysis (DGA) Testing Analysis on 150kv Power TransformersAe Muhammad Rivai et.
1905 | P a g e
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Volume 13.
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php/infokum RESULTS AND DISCUSSION The analysis used two methods to determine the condition of this transformer: TDCG and Key Gases.
Analysis using the TDCG method The TDCG method for Dissolved Gas Analysis (DGA) analysis involves summing the values of Hydrogen (H.
Acetylene (C2H.
Ethylene (C2H.
Ethane (C2H.
Methane (CH.
, and Carbon Monoxide (CO).
The following are the TDCG results obtained from the Dissolved Gas Analysis test on the power transformer at the Titi Kuning substation.
Table 6.
TDCG Results For Power Transformer 1 At The Titi Kuning Substation Gas
H2 CH4 CO C2H4 C2H6 C2H2 TDCG
Nilai .
70 266 514 22 Referring to Table 3, the TDCG calculation results in Table 6 are condition 2.
The results above indicate higher-than-normal levels of flammable gas.
Any flammable gas exceeding the specified levels requires immediate additional investigation.
Table 7.
TDCG Results Of Power Transformer 2 At The Yellow Substation Gas
H2 CH4 CO C2H4 C2H6 C2H2 TDCG
Nilai .
8 Referring to Table 3, the TDCG calculation results in Table 7 are condition 1.
The results above indicate that the transformer is operating satisfactorily.
The transformer can operate normally.
Analysis Using the Key Gases Method Dissolved Gas Analysis using the key gases method is a simple yet effective method for identifying the type of damage or abnormalities in a transformer based on the content of certain gases, such as Ethylene (C2H.
Carbon Monoxide (CO).
Hydrogen (H.
, and Acetylene (C2H.
in the transformer's insulating oil.
Table 8.
TDCG Results Of Power Transformer 1 At The Yellow Substation Indikasi Gas Dominan Konsentrasi Persentase Terhadap .
TDCG Thermal Oil Ethylene C2H4 Thermal Oil Ae Selulosa Carbon Monoxide Electrical Ae Partial Hydrogen H2 Discharge Electrical Ae Arching Acetylene C2H2 Dissolved Gas Analysis (DGA) Testing Analysis on 150kv Power TransformersAe Muhammad Rivai et.
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Volume 13.
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Percentage of Key Gases in Transformer 1 Figure 5 shows the dominant amount of carbon monoxide (CO) gas, indicating overheating in the transformer oil and insulating paper.
Table 9.
Results Of The Key Gases Method For Power Transformer 2.
Substation.
Yellow Dots Indikasi Gas Dominan Konsentrasi Persentase Terhadap .
TDCG Thermal Oil Ethylene C2H4 Thermal Ae Selulosa Carbon Monoxide Electrical Ae Partial Hydrogen H2 Discharge Electrical - Arching Acetylene C2H2 Figure 6.
Percentage of Key Gases in Transformer 2 Figure 6 shows the dominant amount of carbon monoxide (CO) gas, as in Transformer 1, indicating overheating in the transformer oil and insulating paper.
Dissolved Gas Analysis (DGA) Testing Analysis on 150kv Power TransformersAe Muhammad Rivai et.
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Volume 13.
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php/infokum CONCLUSION Based on the research results and data analysis, the following conclusions can be drawn:
The condition of the insulating oil sample for power transformer 1 is category 2.
Abnormalities in power transformer 1 are evident from the TDCG value of 1001 ppm, and the Key Gases method found carbon monoxide (CO) gas to be dominant.
This is due to excessive heat in the transformer insulating oil and insulating paper.
Monthly Dissolved Gas Analysis testing is necessary to ensure the accuracy of the transformer insulating oil The TDCG value for transformer 2, 206 ppm, indicates condition 1.
The transformer can operate normally, but it should be noted that the Key Gases method analysis revealed carbon monoxide (CO) gas, indicating excessive heat in the transformer insulating oil and insulating paper.
Retesting is necessary to confirm the actual condition of the transformer insulating oil.
Dissolved Gas Analysis (DGA) testing results can assist in analyzing abnormal conditions in a transformer.
If necessary, comparative testing can also be conducted using laboratories at other PLN units to confirm the results.
If done correctly, transformer failures will be minimized.
REFERENCE