Correction of DGA Results in Transformers and Accessories Equipped With a Nitrogen Blanket
Abstract
In HV transformers and accessories (e.g., bushings) equipped with a nitrogen or air blanket (e.g., power and wind turbine transformers), gases formed by faults in the transformers partially dissolve in the oil and partially migrate to the gas blanket, following the physical chemistry principle of Henry’s law, with the less soluble gases such as H2, CH4and CO migrating preferentially to the gas blanket. DGA analysis of the oil therefore is not representative of the total amounts of gases produced by the fault, resulting in wrong fault identifications and diagnoses. To alleviate this problem, an equation derived from Henry’s law is proposed in this paper to correct DGA results measured in the oil, taking into account the gases that have migrated to the gas blanket.
Fields of Study & Subjects
Power Transformer Diagnostics and Insulation
High voltage insulation and dielectric phenomena
Power Systems Fault Detection
Publication details
- Journal / source
- IEEE Transactions on Dielectrics and Electrical Insulation
- Publisher
- Institute of Electrical and Electronics Engineers (IEEE)
- Volume
- 33
- Issue
- 3
- Pages
- 2319–2320
- Publication date
- 24 March 2026