Since 1995, the Research Department at TPC has worked on simulation tools and completed a total of 62 TRANSFORMER PROTECTOR (TP) life tests to increase word knowledge on transformer explosions phenomena and explosion prevention technologies.
As a result, since 1999 more than 60 publications have been published and presented in well-known organizations such as IEEE, CIGRE, PowerGen, TechCon, Doble, etc.
To study the phenomena that occurs during transformer explosions, 2 test campaigns were carried out:
- In 2002, 28 TP tests on small transformers performed by Electricité de France (EDF)
- In 2004, 34 TP tests on large transformers performed by the CEPEL High Voltage Laboratory, Brazil
In 2002, the first TP test campaign demonstrated for the first time ever that the rupture of insulation inside transformer dielectric oil was not ruled by conventional physic rules, previously used by all authors.
During the EDF test campaign, it was discovered that:
- The First Dynamic Pressure Peak reflects on all obstacles, creates multiples secondary pressure peaks that build up the static pressure inside transformers during 5 to 100 milliseconds, depending on tank sizes.
- Only the static pressure provokes transformer tanks explosion and fire.
As performing regular tests for each transformer type would not be cost effective, since 1995 a compressible two-phase flow Computerized Fluid Dynamic (CFD) simulation tool has been developed. The experimental tests have been used to validate CDF simulations. To this model, a dynamic Fluid Structure Interactions (FSI) package has been added to check transformer tanks resistance to stresses during low impedance faults. These simulations definitively show the TP efficiency to prevent transformer explosion and fire.
In addition to the 62 TP tests, at least 25 TP Known Activations during transformer normal operation have:
- Validated the research simulations for TP calibration
- Demonstrated the TP efficiency to prevent transformer tank explosions and oil fires