How to prevent the explosion of oil immersed transformer
Writer： Hengfeng you electric Time：2023-04-19 views：times
Oil immersed transformer explosion accidents occur frequently. Because the explosion process of oil immersed transformer is a relatively slow development process, once the explosion occurs, there will be casualties and huge economic losses, which can be said to be very frightening. Because the operability of oil immersed transformer in the process of explosion is relatively large, it is an important place. In order to prevent the explosion accident of oil immersed transformer, we should start with "prevention".
1. Prevent overload operation of oil immersed transformer: if it is overloaded for a long time, it will cause coil heating, gradual aging of insulation, short circuit between boxes, phase to phase short circuit or short circuit to ground and oil decomposition;
2. Prevent aging and damage of oil immersed transformer iron core insulation: aging of iron core insulation or damage of clamping bolt bushing will cause great eddy current in iron core, and long-term heating of iron core will cause insulation aging.
How to prevent the explosion of oil immersed transformer
3. Prevent inadvertent damage to insulation during maintenance: when repairing the hanging core of oil immersed transformer, pay attention to protecting the coil or insulating sleeve. If any scratch damage is found, it shall be handled in time.
4. The low-voltage unbalanced current of oil immersed transformer shall not exceed 25% of the rated value; The allowable variation range of power supply voltage of oil immersed transformer is plus or minus 5% of rated voltage
5. Ensure good contact of wires: poor contact of internal connectors of coils, poor contact of connecting points between coils, contacts leading to bushings at high and low voltage sides, and poor contact of each fulcrum on tap changer will cause local overheating, damage insulation, short circuit or open circuit. At this time, the generated high-temperature arc will decompose the insulating oil and produce a large amount of gas, which will increase the pressure in the oil immersed transformer. When the pressure exceeds the set value of gas breaker protection without tripping, explosion will occur.
6. Maintain good grounding: for the low-voltage system with protective zero connection, the neutral point at the low-voltage side of the oil immersed transformer shall be directly grounded. When the three-phase load is unbalanced, there will be current on the zero line. When the current is too large and the contact resistance is large, high temperature will appear at the grounding point and ignite the surrounding combustible materials.
These explosion prevention measures of oil immersed transformer should be paid attention to all the time, take preventive measures and take active prevention. If the oil immersed transformer really explodes, it is too late to cry
