Gassing is a broad term that speaks to the detection of a potential problem in a transformer by the use of DGA (Dissolved Gas Analysis). DGA measures minute amounts of gas that might be dissolved in a transformers oil. Transformer oil is an insulator that helps prevent electrical current from arcing within the transformer.
There are many types of gasses that can be detected by DGA with each gas suggesting a different type of problem within the transformer. Some gas readings suggest more serious problems than others. Moreover, the relative proportion of each gas can often help identify where in the transformer the fault may exist. In recent years, DGA testing has become both inexpensive and fast.
Transformers that are gassing may operate for years without failing, but in other cases, gassing transformers can fail very quickly.
There are multiple firms and people who can perform quality DGA, however, several manufacturers of testing equipment, testing firms, and people within these firms have reputations as being more conservative in their evaluation of the potential problem. Accordingly, it is important that any DGA testing be done in a consistent manner so appropriate baselines can be set and, most importantly, changes in DGA readings can be monitored with strong data credibility.
The historical standard of DGA being tested annually has gone by the wayside; many power generation businesses test the health of their most important transformer assets more frequently to ensure any problems are recognized at their earliest stages. When a DGA test suggests a problem, some firms believe it prudent to test or evaluate the gassing transformer daily to see if a catastrophic failure is likely.
In the case of a gassing transformer, the typical first step is to adjust the loading of the transformer and to monitor the results of the change by frequent DGA analysis. An evaluation of the surrounding or connected equipment should also be done; a transformer is part of a system and as such there might be transformer problems caused by exterior connections, equipment or gauges. Additionally, a review of both present and prior environmental conditions should be done; recent precipitation and temperature shifts should be taken into consideration. The original equipment manufacturer may be contacted to see if the gassing is an issue that they have encountered with similar models.
If DGA readings are not resolved by the initial steps, or if changes in the DGA readings continue, more extensive testing of the transformer may be required. Such tests might include acoustic or electric partial discharge (PD), winding resistance, magnetizing currents, frequency response analysis (FRA) and polarization spectrum measurements. One or more of these tests may indicate the necessity to drain the transformer of its oil and undertake detailed internal inspections of the insulation paper and the transformers other components.
Importantly, a gassing transformer should make the owner evaluate what would happen if the transformer were to fail and how a replacement can be obtained to minimize any downtime. The total cost of buying and installing new equipment is often far less than the cost of business interruption when all related costs, loss of profits and other issues are considered.
Our Value Proposition
If you are a power generation facility, a third party firm that works with a client in the power generation industry, or an insurance company that insures worldwide power generation risks, Fast-Track Power LLC offers the following value:
Reduce the Cost of Business Interruption
We seek to help you (or your client) reduce the very high cost of business interruption by providing expedited “fast-track” access to the necessary high-voltage equipment and services at competitive terms. We are your global fast-track resource for both equipment and services on a turn-key / seamless basis.
Provide Expert Knowledge for Better Decision Making
By injecting competition and experience into the process of a fast-track situation, Fast-Track Power LLC positions you to receive significant cost savings, reduced risk, and enhanced decision making knowledge.
In a recent failure of a large GSU transformer, the presence of competition in the fast-track replacement process achieved a client over $200,000 in savings from the firm that had originally been contacted to source a replacement transformer. Moreover, the client and its financial partners also gained the direct attention of the most experienced people (who used their expertise to lower the chance of a problem during the replacement process) and a better understanding of the universe of credible options.