Electric Transformer Common Problem Solutions

1. Treatment of electric transformer oil leakage

Because there are many reasons for transformer oil leakage, it is necessary to carry out different forms of welding treatment for the leakage oil formed by different reasons. The cracks on the plane can be treated by direct welding. For the situation where the cracks are on different planes, the iron plate needs to be cut into a spindle shape for repair welding to avoid oil leakage later. For different oil leakage areas, different treatment methods need to be used. The oil leakage at the oil tank needs to be directly welded to the plane area, and the cracks in the corners need to first find the location of the leakage and then carry out special welding. The welding requirements at the corners take into account the parameters of the internal stress in the corner to avoid re-leakage due to exceeding the internal stress limit. The oil leakage at the low-voltage side bushing needs to be cleaned first, and the short lead and the overstretching of the busbar are eliminated. After adjusting the lead length and the busbar expansion joint, the fault can generally be solved. Regarding oil leakage at the explosion-proof pipe, if the oil tank ruptures due to excessive internal pressure of the transformer, it is necessary to remove the explosion-proof pipe and install pressure relief valves and other equipment.

2. Treatment of multi-point grounding of iron core

The multi-point grounding method of the iron core of the electric transformer can be divided into two methods. One is to open the box for inspection. This simple and direct method is used to remove the grounding point on the outer box cover of the transformer, and at the same time, the use of the insulating cardboard is checked. Find out and replace in time the conditions that affect normal use. Another method is to use the DC current shock method to burn off the redundant iron core grounding points by the thermal effect of the DC current. Generally, the remaining grounding points can be dealt with by four to five DC current shocks.

3. Transformer damp treatment

After the electric transformer is wet, two methods of offline treatment and online treatment can be selected. Compared with online processing, offline processing is limited by application conditions, and there are many difficulties in the implementation process. The maintenance process requires a long-term power failure processing, and may also cause accelerated aging of the transformer insulation. Off-line processing needs to consider the characteristics of different voltages in terms of capacity and structure, and perform dehumidification and heating treatment on them. The online treatment mainly removes the moisture in the transformer oil through online oil filtering, and sprays water into the vacuum eye, so that the gas and moisture in the vacuum container are transferred to the environment.