Autor: Nova Energy Consulting Pty Ltd
Interpret Dissolved Gas Analysis like a pro
The challenge of managing Power Transformers
A critical aspect of managing assets is to understand their condition, their
performance against the organisation's objectives and the level of risk they
Power transformers and other insulating liquid-filled assets are critical
component of electrical grids. These are typically very expensive assets with
long replacement lead times.
Utilities and other asset intensive organisations depend on assessments
performed by Subject Matter Experts (SME) to make the most effective and
efficient decisions. These SMEs are also busy dealing with all sort of
emergencies and requirements from the day-to-day operation of the business.
Based on many years of accumulated experience, international reliability
surveys and the hard work of many of these SMEs around the world, the industry
has developed a range of diagnosis techniques that assist in the management of
One of the most common techniques to assess the condition of Power
Transformers is through regular insulating liquid sampling and analysis. The
Dissolved Gas Analysis component of this suite of tests is one of the most
useful techniques to understand the transformer's condition.
This knowledge has been captured in the form of technical papers, guidelines
and various study reports. These documents are rich with information and
knowledge about the best way to assess the condition of each asset.
This documents have to be translated into an actionable algorithm or
calculation in order to be useful. Without a standard implementation, most
teams develop their own tools and calculation spreadsheets.
The use of digital tools to assist condition assessment
Digital tools can provide these SMEs the information they need to make
opportune decisions and provide sensible recommendations.
When these decisions are recorded on digital platforms, the rest of the
organisation benefits from having a consistent approach to making these
decisions. Whether they are being made by a veteran in the industry or a young
engineer or technician at the early stage of their careers.
A well-designed digital tool has the potential of supercharging the skills and
experience of asset managers.
If you’ve ever tried to apply any of the available analysis guidelines, you’ll
know that some of them are dozens of pages worth of information. Wouldn’t it
be nice if all those rules were condensed in easy-to-use formulas that can be
applied to your existing DGA data?
If only there was a tool that summarises all this knowledge and helps SMEs
apply these algorithms easily and consistently.
xDGA was created with this purpose in mind.
What is xDGA?
xDGA is an Excel add-in tool that implements a set of custom
formulas. These formulas enable is users to run industry best-practice
algorithms to evaluate and assess the results of Dissolved Gas Analysis in
Liquid Filled Electrical Apparatuses such as Power Transformers, On-Load Tap
Changers, Circuit Breakers, etc.
The custom formulas are packaged as an Excel add-in which doesn’t require any
additional software installed on your computer. Simply install xDGA from one
of the available sources and you'll be up and running in no time. Read our
The main components of xDGA are as follows.
These custom formulas allow you to:
Normalise the information required for further analysis using a DGA
Perform automatic conversions of the "triangular" and "pentagonal"
coordinates of the Duval chart into cartesian X,Y coordinates. This is
useful if you want to create Duval charts in your workbook.
Run individual rules and diagnosis techniques such as Rogers Ratios, Duval
Triangles, Duval Pentagons and sections of the IEC 60599 interpretation
Run a full assessment as per the IEC 60599 guidelines and get a "NORMAL",
"ALERT" or "ALARM" assessment.
Read more about this feature in the Formulas section of the documentation.
Duval triangles and pentagons charts
xDGA also has the functionality of inserting any of the Duval
Triangles and Pentagons as Excel charts.
Each chart has been carefully crafted and formatted to be easily extensible by
the user. Each zone is clearly labelled and all source coordinates to draw
these areas are stored in a separate worksheet.
These charts can be inserted in seconds and will enhance any existing or new
Read more about this feature in the Charts section of the documentation.
DGA database and report templates
Building on all these features, xDGA provides you with two starter templates.
One inserts a new worksheet that contains an Excel table DGA database that is
preformatted to act as a database for all your reporting needs.
The second is a template for a full analysis report for an individual
transformer. This report relies on the DGA database and it contains all the
necessary formulas and formatting to just select a transformer from the
Read more about this feature in the Reports section of the documentation.
What are you waiting for? The add-in can be downloaded from any of the
Microsoft sources (see Installation) and you'll be up and running in a couple
With one free month to try out all of its features, there is no risk to you or
your team. If you don't like it, you don't buy it.
We hope you enjoy it and we welcome any feedback you might have.
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