FR3™ natural ester helps achieve greater continuous load capacity to better handle demand fluctuations

FR3™ natural ester helps achieve greater continuous load capacity to better handle demand fluctuations

Vol. 5 Issue 1

Tamini power transformer success story


Abstract
Power flow within networks is becoming increasingly complex with high probability of unforeseen peak demands throughout the day. The use of thermally upgraded kraft (TUK) paper and FR3™ natural ester allowed TAMINI to successfully design, manufacture and test an autotransformer with increased load capacity (375 MVA vs 250 MVA nominal rating) for Italian system operator TERNA. With this solution the power demand fluctuations are better handled, energy losses are reduced, while environmental protection and fire safety are increased.

Keywords: FR3™ natural ester, fire safety, increased loadability

With transformers a major cost element for any utility or grid company, managing utilization is critical to cost-effectively and reliably managing the grid. Using TUK paper and Cargill’s Envirotemp™ FR3™ natural ester fluid, TAMINI was able to successfully design, manufacture and test an autotransformer with significantly more load capacity (375 MVA vs 250 MVA nominal rating), while maintaining the temperature rise allowed for high-temperature insulation materials and the expected insulation life. The enhanced load flexibility and appropriately sized transformer capacity allow TAMINI’s customer, TERNA, to better handle demand fluctuations and ultimately effectively reduce energy loss. Terna is the largest transmission system operator in Europe and a majority owner of the high voltage transmission grid in Italy.

The autotransformer’s nominal rating of 420 kV/135 kV 250 MVA with continuous load capacity up to 375 MVA was validated by routine, type and special tests, including short circuit withstand capability performed at CESI in Rondissone, Italy. The transformer was installed in the Terna’s substation of Tavazzano in December 2017.

“Power flow within networks is becoming increasingly complex. There is a higher probability of unforeseen peak demands throughout the day, and we are seeing those demands for longer periods of time. Current loading profiles based on mineral oil transformer limits may not be able to withstand those inconsistent demands,” said Fabio Scattigio, head of the Terna chemical laboratory who was involved in the testing protocol with TAMINI. “The continuous permanent load capacity concept using natural ester represents a real paradigm shift for our industry, as it deeply affects the criteria for transformer selection among electric utilities and grid companies.”