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Interpretation techniques on DGA results
There are several interpretation techniques on transformer oil dissolved gas analyzing results as follows: 1. IEC 60599 Ratios 2. IEEE C67.104, Limits, rates and TDCG 3. Rogers Ratios 4. Kay Gas Method 5. Duval Triangle 6. Trend Analysis 7. New Guidelines for Interpretation of DGA" CIGRE Tast force 15.01.01, ...
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Causes of fault gases in transformer oil
1. In all types of faults, hydrogen is always present.2. Low energy faults, such as corona partial discharges in gas bubbles, or low temperature hot spots, will form mainly H2 and CH4.3. Faults of higher temperature are necessary to form large quantities of C2H4.4. Faults with a very high energy content, ...
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Type of gases in transformer oil
1. Hydrocarbons and Hydrogen Methane (CH4) Ethane (C2H6) Ethylene (C2H4) Acetylene (C2H2) Hydrogen (H2) 2. Carbon Oxides Carbon monoxide (CO) Carbon dioxide (CO2) 3. Atmospheric Gases (non-fault gases) Nitrogen (N2) Oxygen (O2)
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Every DGA starts with the sampling
Thousands of litres in a transformer tank, syringe only 40ml., the sample must be as representative as possible.Appropriate sampling techniques are indicated on ASTM D923, IEC 60567 and in many company specifications.
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3 Key Steps for DGA
There are 3 key steps for transformer oil dissolved gas analysis as follows:1. Oil sample extraction2. Extraction of the gases3. Gases separation & measurement (gas chromatography)
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Why Dissolved Gas Analysis (DGA) is important?
During the last decades, Dissolved Gas Analysis (DGA) has become the most important preventive routine for power transformers. DGA is a simple and non-intrusive oil analysis, that can predict faults via the analysis of the gases generated on the insulating oil. The types of dissolved gases in the oil, ...
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How the Base affects reaction kinetics of Karl Fischer Titration
The type of Base (R'N) and its concentration affect teh overall reaction rate. Traditionally, pyridine was used as the base. However, because of its weak basicity, pyridine can not completely neutralize the alkylsulphurous acid intermediate. As a result, reaction (ROH + SO2 + R'N - [R'NH]SO3R) does not ...
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The Chemistry of Karl Fischer Titration
The Karl Fischer technique for water determination is a titration reaction based on the Bunsen equation as follows:(1) ROH + SO2 + R'N - [R'NH]SO3R(2) [R'NH]SO3R + H2O + I2 + 2R'N - 2[R'NH]I + [R'NH]SO4RRemarks: R'N = base, ROH = alcohol, typically methanolThe oxidation of alkylsulfite to alkylsulfate ...
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High Performance Liquid Chromatography for Fural Analysis
High Performance Liquid Chromatography for Fural Analysis (Furaldehyde in oil)Furaldehydes (Furals) are chemicals formed when cellulose paper degrades due to overheating. The status of solid insulation can be measured using liquid oil insulation. Degrees of Polymerization (DP) is a test done on the paper ...
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Method for Furan Analysis
High-Performance Liquid Chromatography (HPLC) is a reliable method to perform furan analysis on transformer oil. The standards are IEC 61198 and ASTM D5837. IEC 61198: Method for the determination of 2-furfural and related compounds in mineral insulating oils. This International Standard specifies test ...
