Transformer explosions are caused by low impedance faults that result in arcing once the oil loses its dielectricproperties. Oil is then vaporised, and the generated gas is pressurised because the liquid inertia prevents its expansion. The pressure gap between the generated gas bubbles and the surrounding liquid oil generates pressure waves, which propagate and interact with the tank structure. They cause the pressure rise that leads to the tank explosion. These explosions result most of the time in very expensive damages for electricity facilities . Realising that the transformer explosion prevention is the sole effective solution to avoid such financial losses, SERGI designed and patented worldwide the TRANSFORMER PROTECTOR (TP) in 1999.
The TRANSFORMER PROTECTOR (TP) is a transformer explosion and fire prevention technology based on the direct mechanical response of a Depressurisation Set to the tank inner dynamic pressure increase due to a fault. Since transformers always rupture at their weakest point, the Depressurisation Set is designed to be this weakest point in term of inertia to break before the tank explodes. For that purpose, the Decompression Chamber is equipped with a Rupture Disk (RD). Indeed, after an electrical fault has occurred, the pressure rises, and the Depressurisation Set (DS) opens as soon as the pressure close to the TP has reached the calibrated pressure. Oil is then quickly expelled from the transformer tank, through the Decompression Chamber (DC), and into an Oil Gas Separation Tank (OGST), so that the TP depressurises the transformer tank within milliseconds, and prevents the transformer from exploding. Indeed, once the TP has activated, the mechanical energy is evacuated and the transformer is protected even if the electrical arc is still fed for one second.
The TRANSFORMER PROTECTOR (TP) is the only proven solution against transformer explosion and fire. The TP complies with NFPA codes 850 and 851, which recommend Fast Depressurization Systems for all Power Plants and Substations.
The TP is activated within 0.5 to 20 milliseconds, depending on arc locations and transformer size, by the first dynamic pressure peak of the shock wave, avoiding transformer explosions before static pressure increases.
Transformer explosions and fires are very damaging and frequent. A recent one-year research project led to the discovery of 730 transformer explosions in the USA only. Many experts anticipate that the number of failures per year will increase significantly in the near future because of the shorter duration life*. Transformer explosions and fires create environmental pollution, costly plant outages, and are a risk to human lives.
After TP activation, the transformer is saved from explosion and fire. However, most of the companies avoid disclosing any information regarding transformer failure and all other technical details. Nevertheless, to date there are 19 TP known Successful Activations.