Method Development Transformer Overvoltage Protector

French SERGI company recently developed the only technology that can prevent transformer explosion and fire: "transformer protector". This protector is suitable for all types of transformers and load conditioners, including current or new transformer equipment.
The French high-voltage power test laboratory successfully conducted 28 "transformer protector" tests for this product. The protection system succeeded in reducing the pressure in the insulating tank of the transformer when the pressure gradient was between 500 and 1200 bar/sec, ie between 7000 and 17400 psi/sec. Due to the success of this experiment, many power generation companies, transmission and distribution companies, and industrial sectors have included “transformer protectors” in their technical requirements.
Transformers can explode and catch fire because they are not sufficiently protected against rapid changes in the pressure generated by short circuits. To avoid the serious consequences of such accidents, SERGI has developed an in-depth research program since 1995 in order to understand the energy transfer between the arc and transformer insulation oil. In the research, a magneto-thermo-hydrodynamic model was designed to simulate various situations and to quantify the explosion and combustible gas generation. The simulation results show that when a short circuit occurs, the voltage gradient in the transformer insulation tank is 50-500 bar/s, ie 700-7000 psi/s, and the time from short circuit start to the explosion of the transformer tank is between 10 and 50 milliseconds. Faced with such a rapid phenomenon, traditional transformer protection measures are ineffective. Such as circuit breakers, their movement is too slow to prevent the transformer from exploding.
This device is mainly composed of explosion-proof membrane, nitrogen injection device and oil and gas separator. The diameter of the explosion-proof membrane is determined according to the size of the transformer. When the transformer is short-circuited and over-pressured, the isolation valve is opened so that the transformer oil enters the oil-gas separation gas, and the combustible gas is discharged, and the high-pressure nitrogen is injected into the transformer.