The Science Behind R-DGA

Diagnostic software for insulating fluid test data. Push beyond conventional paradigms to a more correct interpretation.

Dissolved gas is not the problem

Under normal operation, transformers do not generate significant amounts of dissolved gas in oil. When they do, something is wrong. A condition has developed within the transformer generating heat, which is then damaging oil or paper insulation. The dissolved gases are symptoms of that underlying problem, not the problem itself. Conventional DGA treats these symptoms with simple concentration limits. Delta-X Research treats the root cause.

From detection to severity in three steps

1

Detect the Fault

Using simple gas concentrations and rates-of-change to detect faults has resulted in understating or, worse, missing problems. Delta-X Research's approach applies fault energy indices, accounts for gas loss, and uses statistical methods to provide a more reliable detection signal.

2

Identify the Fault Type

Once a fault is detected, understanding what type it is guides the maintenance response. Delta-X Research uses the 4-Simplex method, plotting five hydrocarbon gases, which provides more reliable fault type identification than the Duval pentagon, eliminating the ambiguity caused by projecting 5-dimensional data onto a 2-dimensional plot.

3

Assess Fault Severity

This is where Reliability-based DGA makes its most important contribution. R-DGA compares a transformer's fault energy index against a statistical model built from real transformer failure data, producing two risk measures: Cumulative Severity (CSEV) and Hazard Factor (HF).

Two outputs. Both actionable.

CSEV: Cumulative Severity

The percentage of gassing transformers in the failure dataset that would fail before this transformer at its current rate of gas production. A CSEV of 80% means 80% of the transformers in the comparison group would fail first.

HF: Hazard Factor

The probability that this transformer will fail within the next year if it continues producing gas at the current rate. A concrete, actionable number for risk management.

The most accurate interpretation of DGA available

IEEE and IEC standards acknowledge that DGA interpretation is, in their own words, ‘more of an art than a science.’ Delta-X Research has spent 30+ years working to change that. R-DGA provides maintenance teams with statistically grounded, failure-data-informed risk assessment. No more guesswork. No more unnecessary false alarms. Just the information you need to make confident decisions.

Peer-reviewed research

The science behind TOA is published in peer-reviewed journals and presented at leading industry conferences including CIGRE, IEEE, and NETA. Dr. Jim Dukarm has been advancing DGA methodology since 1988.

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