Fast Depressurization Technology is recommended by National Fire Protection Association (NFPA) and Indian regulatory body i.e., Central Electricity Authority (CEA) for the safety of transformer against explosion and fire.
In the current landscape, ensuring the safety of transformers against explosions and fires has become a paramount concern. Given their status as one of the most valuable assets in a Substation, addressing this concern has become imperative, which can only be answered through the solutions based on Fast Depressurization Technology.
Oil-filled transformer explosions are due to electrical arcs occurring in transformer tanks. Within milliseconds, arcs vaporize the surrounding oil and the generated gas is quickly pressurized. The pressure difference between the gas bubble and the surrounding liquid oil generates pressure waves, which propagate and interact with the tank. Then, the reflections of the pressure waves build up the static pressure, which rises and leads to the tank rupture This results in dangerous explosions, expensive damages, and possible environmental pollution.
Fast Depressurization System as defined by NFPA should react within millisecond and depressurization the transformer, ensuring the complete safety against explosion and fire. This action is achieved by the direct mechanical response of a Depressurization Set (based on FDS technology) to the tank inner dynamic pressure increase due to an electrical fault. Since transformers always rupture because of the static pressure at their weakest point, the Depressurization Set is designed to be this weakest point in term of inertia to break before the tank explodes.
Thus, during a transformer short circuit, the FDS based solutions are activated within milliseconds by the first dynamic pressure peak of the shock wave generated by the electrical fault and before static pressure increases.
System based on Fast Depressurization technology have undergone several live tests to confirm their compliance with NFPA recommendations.