What are the methods of transformer drying
Writer： Hengfeng you electric Time：2023-04-03 views：times
People who know the transformer should know that the transformer needs boring treatment. The transformer boring can avoid short circuit of the transformer to a certain extent and various faults of the transformer. However, there are many boring processes and main boring methods for transformers.
1. Winding copper loss boring method: through the transformer winding, the power generation itself generates heat, heats the winding insulation, has small operation volume, fast temperature rise and saves time. The defect is that the power capacity required is large.
2. Oil tank iron loss vacuum drying method: vacuum drying is carried out through the transformer oil tank itself, which requires small power capacity and low voltage. The defect is that the workload is large, the boring time is long, and a lot of data, equipment and calculation analysis are required.
3. Hot air drying method: put the transformer in the drying room and apply hot air for drying treatment. The drying room can be combined according to the size of the transformer, and the wall panel is covered with asbestos board or other canvas or asbestos linen impregnated with fire-proof solution.
4. Zero sequence current boring method: the transformer winding is energized to heat the oil tank, iron core and winding. The defect is that before and after the transformer is dry, it needs to drain oil, hang the core and change the winding connection method. There is a large amount of work and the temperature is not easy to control, which may cause partial overheating.
5. Zero sequence short circuit boring method: this method is an inductive method between zero sequence current boring method and winding copper loss boring method. The former is heated by iron loss and the latter by copper loss. The zero sequence short circuit boring method combines the two methods for boring treatment.
6. Induction heating method: put the body in the original oil tank, surround the oil tank with coils, and use the eddy current heating of the tank skin for boring treatment. The tank wall temperature shall be controlled below 115 ℃ ~ 120 ℃, and the body temperature shall not exceed 90 ℃ ~ 95 ℃.
7. Vacuum drying method: take air as the heat carrying medium, gradually preheat the transformer body or winding to about 105 ℃ and start vacuum pumping. This method has simple equipment and convenient operation. The defect is slow heat transfer, long production cycle, boring and incomplete, which is difficult to meet the insulation requirements of transformer.
8. Vapor phase vacuum drying method: this method uses a special fire oil vapor as the heat carrier, the fire oil vapor introduced into the vacuum tank condenses in the transformer body, releases a lot of heat energy, and then heats the dryer body. This method has the advantages of large heat energy, more uniform and complete dryness, high efficiency and less damage to insulation data. The defect is that the cost is high and the structure is complex. At present, it is only limited to the boring treatment of large transformers above 110kV.
The dry methods for these transformers have their own advantages and disadvantages. The selection of cooperative dry method must be determined according to their own conditions. Of course, it should be noted that when there is no oil and dry, the transformer body temperature shall not exceed 95 ℃, and when there is oil, it shall not exceed 80 ℃, so as to avoid oil aging.
The above contents are some boring introductions about how the transformer manufacturer carries out. If you still don't know, you can call Hengfengyou electric transformer manufacturer's operator + 86 15853252696. Maybe if you need more information, you can click send email for consultation hfy@hengfengyou.com 。
