Transformer fault diagnosis by transformer experts

Your DGA shows that something is wrong with your transformer:

  • Find out if your transformer really has a problem and how to solve it.

    Duval triangle and pentagon for transformer DGA interpretation
  • Know what to do with online monitor data.

    Transformer DGA trend from online DGA monitor
  • Get the most out of DGA by customizing it to the transformers in your fleet.

    Transformer fleet risk assessment

Our DGA Interpretation Services

Click on a service to learn more

  • Transformer fault diagnosis

    Initial assessment of your transformer

    We determine whether your transformer has a problem by examining its DGA values along with its design, quality issues, and service conditions. We provide a clear assessment of your situation and give you a set of recommended actions to follow. The fee for this initial assessment is €500 per transformer. Additional consultations about the same transformer will be quoted separately.

    Consulting process step-by-step

    1. Contact us to submit your initial assessment payment online.
    2. We will then ask you to provide detailed information about your unit and its DGA history. Once we receive this, we will give you a time estimate for our delivery.
    3. Our experts will assess the condition of your unit taking into account all information provided and suggest follow up action if necessary.
    4. Our initial assessment service is complete at this point. If you need additional consultation then we will send you a separate quote.

  • Daily online monitor diagnosis

    We provide an initial assessment your transformer and then interpret your online monitor DGA daily (as soon you send us the data). We give you early warning if the situation deteriorates and we discuss with you a course of action to minimize chances of catastrophic failure.

    Consulting process step-by-step

    1. Contact us with our online form to get started.
    2. We will then ask you to provide: (a) detailed information about your unit, (b) its DGA history including values from both your lab and your monitor, (c) your monitor type and model, (d) a sample Excel report produced by your monitor, and (e) the period you wish to use our online DGA interpretation service (minimum one month).
    3. We will send you a quote and, if you wish to proceed, an invoice.
    4. Once your payment is received, our experts will conduct a initial study of your unit and provide a first assessment.
    5. You send us updated DGA data every day for our experts to examine. Each time you will receive a progress report and specific comments if the case needs special attention.

  • Transformer fleet health and risk assessment

    We start the assessment of your fleet by calculating custom DGA limits based on your fleet’s designs, unit types, operation conditions, and known issues. This allows us to identify the units in need of further attention. We can then assist you in monitoring critical units, inspecting them, and discussing with the manufacturer to find a solution.

    Consulting process step-by-step

    1. Contact us with our online form to get started.
    2. We will then ask you for information about your fleet and give you a quote based on this. If you wish to proceed, we will then send you an invoice.
    3. Once your payment is received, we will ask you to provide detailed information about your units as well their DGA values.
    4. Our deliverables will be: (a) custom DGA limits for each type of transformer in your fleet to make your future DGA more relevant, (b) ranking of your units by problem severity along with proposal for actions.

Please note that we provide our service to transformer users and transformer manufacturers only.


Our Expertise

Our team includes experienced transformer consultants of international reputation. We also have the IT expertise to provide cloud-based web services. To learn more about us, please visit our general consulting website Trafoexperts.

Ugo Piovan transformer diagnostics expert
Ugo Piovan

20+ years of experience in transformers for applications up to 120kA, 800kV DC, and 1200kV AC. Internationally recognized transformer expert. Chairman/member of several CIGRE, IEC, and IEEE committees.

Baudilio Valecillos transformer diagnostics expert
Baudilio Valecillos

10+ years of experience in transformers with expertise in fast transients, measurements, and 3D finite element simulations.

Linda Wang DGA diagnostics tools developer
Linda Wang

Computer engineer with expertise in both frontend and backend web development.


Frequently Asked Questions

How are you different from other DGA service providers?

Most DGA service providers are chemical labs which treat transformers as black boxes. Their knowledge comes only from statistical correlation between measured gasses and observed faults. In contrast, our knowledge of transformer design and operation allows us to understand the underlying causal relationship (not simple correlation) between gasses and possible faults. Therefore, we support you in getting your problem solved instead of only advising a new DGA after a specific amount of time. For example, we can start by suggesting other types of tests to validate the initial DGA diagnosis.

Others provide DGA interpretation tools so that I can get results immediately. Can you do the same?

No. With us, you will always have transformer experts looking at your data. Your data won't be just automatically processed by a generic report generator. Our experts will take the time to go through them so it may take a few days to get back to you.

Why do you ask so many more questions about my transformers than other DGA service providers?

Others treat transformers as black boxes, so this additional information would be of little use to them. We understand transformers. Therefore, any information you can give us about their designs and service conditions is a useful piece of the puzzle for us.

How quickly will I receive your assessment of my transformer(s)?

It depends on the number of transformers you wish us to assess, the information available, our workload, and whether we receive payment in a timely manner. We will communicate our delivery time after we receive information about your transformers.

Can I send you an oil sample to analyze?

No. We are not chemical engineers. We do not have the expertise and equipment to determine dissolved gas values. Many competent labs already provide this service quickly and economically. Our added value is in the interpretation of the results reported by the labs.

I have oil samples from the OLTC of my unit. Do you provide interpretation for this too?

At the moment, not for routine checks. Although we are experienced with this work, it is not yet fully supported by the software tools we developed. In case of emergencies, please contact us and we will discuss what can be done.

My transformer is filled with non-mineral oil (silicone, FR3, Midel, Biotemp). Do you provide interpretation for this case too?

At the moment, not for routine checks. Although we are experienced with such cases, it is not yet fully supported by the software tools we developed. In case of emergencies, please contact us and we will discuss what can be done.

Why do you give me a spreadsheet to fill with my DGA results? Can't I just send you the lab reports?

We want to deliver maximum value at minimum cost. When you provide us with clear data in a format defined by us, we can focus on the interpretation and keep cost to a minimum. If you would like us to enter your data in the spreadsheet for you, we can do it for a flat fee of €200 (up to 20 analysis points) per unit.

How can I benefit from custom limits you developed for my fleet if my oil chemical analysis lab uses an automatic DGA interpretation software that cannot apply these custom limits?

This is a very common situation. Their software may also be using out of date interpretation methods. This is not surprising since these labs are staffed by chemical engineers whose focus is on carrying out chemical analyses. We can offer you a subscription service where you forward your DGA results to us. The results will be interpreted by our transformer experts taking into account your custom DGA limits. Please contact us for a quote.

My transformer's DGA looks fine but I am concerned about its other diagnostic results (FRA, PD, DFR, power factor, etc.). Can you help?

Sure, our transformer experts are experienced in assessing multiple diagnostics. Please contact us. We will ask you to fill a form on your unit, tell us what your problem is, and we will come back to you with a custom quote.

Why do you provide service to transformer users and manufacturers only?

We strongly believe that our services must deliver significant value to our customers. Having someone between us and the user can deflate this value.


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