How to prolong the life of oil immersed transformer
Main contents of operation and maintenance of oil immersed transformer
1. prevent transformer overload operation. If the overload is running for a long time, it will cause the heating of the coil to cause the insulation to gradually grow old, resulting in short circuit between boxes, short circuit between phases or short circuit to the ground and decomposition of oil.
2. guarantee the quality of insulating oil. Transformer insulation oil in storage, transportation or operation and maintenance, if the oil quality is poor or impurities, excessive moisture, will reduce the insulation strength. When the insulation strength is reduced to a certain value, the transformer will short-circuit and cause an electric spark, an arc or a dangerous temperature. Therefore, the transformer in operation should be regularly tested for oil quality, and the unqualified oil should be replaced in time. Add the security engineer site to the collector
3. prevent the aging damage of transformer core insulation. Iron core insulation aging or clamping bolt casing damage will cause the core to produce large eddy currents, resulting in long-term insulation of iron core resulting in insulation aging.
4. prevent the overhaul to destroy the insulation inadvertently. When the transformer is overhauling the core, it should pay attention to the protection of the coil or the insulating sleeve. If there is any scratch damage, it should be dealt with in time.
5. ensure that the wire is in good contact. The internal contact of the coil is bad, the connection point between the coils, the top of the coils, the connection point of the sleeve of the low pressure side, and the bad contact of the branches on the splice switch will produce local overheating, destroy the insulation, and have short circuit or circuit breakage. The high temperature arc generated at this time will cause the insulating oil to decompose and generate a large amount of gas, and the pressure inside the transformer will be added. Explosion will occur when the pressure exceeds the protection value of the gas breaker and does not trip.
6. prevent electric shock. Power transformers usually come from overhead lines, and overhead lines are easily struck by lightning. Transformers will burn through insulation.
7. short circuit protection is reliable. When the transformer coil or load is short circuited, the transformer will bear a considerable short circuit current. If the protection system fails or the protection value is too large, it is possible to burn out the transformer. For this reason, a reliable short-circuit protection device must be installed.
8. keep good grounding. For the low voltage system with the protection of zero, the neutral point of the low voltage side of the transformer should be directly grounded when the three-phase load is unbalanced, the zero line will appear current. When the current is too large and the contact resistance is large, the grounding point will have high temperature and ignite combustible materials around it.
9. prevent overheating. The change of temperature should be monitored during the operation of the transformer. If the coil wire of the transformer is a grade a insulation, its insulators are mainly paper and cotton yarn. The temperature has a great influence on the insulation and service life, and the insulation life will be reduced by about 50% when the temperature rises 8 degrees C. The transformer operates at a normal temperature (90 degrees C) and has a life span of about 20 years. If the temperature rises to 105, the life span is 120 centigrade for 7 years and 5, and the life span is only two years. Therefore, when the transformer is running, it is necessary to maintain good ventilation and cooling, and if necessary, adopt mandatory ventilation to reduce the temperature rise of the transformer.
1. prevent transformer overload operation. If the overload is running for a long time, it will cause the heating of the coil to cause the insulation to gradually grow old, resulting in short circuit between boxes, short circuit between phases or short circuit to the ground and decomposition of oil.
2. guarantee the quality of insulating oil. Transformer insulation oil in storage, transportation or operation and maintenance, if the oil quality is poor or impurities, excessive moisture, will reduce the insulation strength. When the insulation strength is reduced to a certain value, the transformer will short-circuit and cause an electric spark, an arc or a dangerous temperature. Therefore, the transformer in operation should be regularly tested for oil quality, and the unqualified oil should be replaced in time. Add the security engineer site to the collector
3. prevent the aging damage of transformer core insulation. Iron core insulation aging or clamping bolt casing damage will cause the core to produce large eddy currents, resulting in long-term insulation of iron core resulting in insulation aging.
4. prevent the overhaul to destroy the insulation inadvertently. When the transformer is overhauling the core, it should pay attention to the protection of the coil or the insulating sleeve. If there is any scratch damage, it should be dealt with in time.
5. ensure that the wire is in good contact. The internal contact of the coil is bad, the connection point between the coils, the top of the coils, the connection point of the sleeve of the low pressure side, and the bad contact of the branches on the splice switch will produce local overheating, destroy the insulation, and have short circuit or circuit breakage. The high temperature arc generated at this time will cause the insulating oil to decompose and generate a large amount of gas, and the pressure inside the transformer will be added. Explosion will occur when the pressure exceeds the protection value of the gas breaker and does not trip.
6. prevent electric shock. Power transformers usually come from overhead lines, and overhead lines are easily struck by lightning. Transformers will burn through insulation.
7. short circuit protection is reliable. When the transformer coil or load is short circuited, the transformer will bear a considerable short circuit current. If the protection system fails or the protection value is too large, it is possible to burn out the transformer. For this reason, a reliable short-circuit protection device must be installed.
8. keep good grounding. For the low voltage system with the protection of zero, the neutral point of the low voltage side of the transformer should be directly grounded when the three-phase load is unbalanced, the zero line will appear current. When the current is too large and the contact resistance is large, the grounding point will have high temperature and ignite combustible materials around it.
9. prevent overheating. The change of temperature should be monitored during the operation of the transformer. If the coil wire of the transformer is a grade a insulation, its insulators are mainly paper and cotton yarn. The temperature has a great influence on the insulation and service life, and the insulation life will be reduced by about 50% when the temperature rises 8 degrees C. The transformer operates at a normal temperature (90 degrees C) and has a life span of about 20 years. If the temperature rises to 105, the life span is 120 centigrade for 7 years and 5, and the life span is only two years. Therefore, when the transformer is running, it is necessary to maintain good ventilation and cooling, and if necessary, adopt mandatory ventilation to reduce the temperature rise of the transformer.