For more than 20 years the BASF headquarters in Ludwigshafen have been using transformers from ABB. Although two 1.25 MVA RESIBLOC cast-resin transformers have been running without any problems since 1991, a voltage test with partial electrical discharge monitoring was recommended in order to check the condition of all running transformers.
In order to reduce the downtime to a minimum, ABB employees at the German service location in Halle used an on-site testing container instead of taking the measurements in a laboratory.
"This kind of testing container is normally used for power transformers which need to be checked in place because of transport restrictions," said Nils Leenen, Head of Marketing & Sales RESIBLOC transformers. Performing the tests at the customer site on the cast-resin transformers not only reduced the downtime but also the costs for disassembling, transport and assembling. It also mitigated the possible risk of damage to the transformers during these steps.
Age has no impact
The tests, which were the result of a conversation between representatives of BASF and ABB during the RESIBLOC Roadshow 2011, were conducted based on the inspection records of the valid standards IEC-60076 and VDE-0532 and remained inconclusive.
Significant partial discharge signals above the existing local level were not detected. None of the measurements in the field trial indicated any effects of aging on the insulating materials.
"With this solution we bring the testing laboratory to the transformer and not the other way around," said Matthias Steiger, Project Manager of the ABB service location in Halle. The concept convinced Ulrich Ehrmann, Plant Engineer at BASF. "We are glad to have ABB as a reliable business partner. With this on-site measurement we are able to pull conclusions on the condition of our installed base," said Ulrich.
