Cause and Treatment of Transformer Light Gas Action
Causes for transformer light gas action:
(1) Air enters the transformer because the oil filtration, refueling or cooling system is not tight;
(2) The oil level is lower than the light gas buoy of the gas relay due to temperature drop or oil leakage;
(3) transformer failure generates a small amount of gas;
(4) The transformer has a crossing short circuit fault.
Under the action of crossing fault current, the oil flow speed between the oil gap is accelerated. When the pressure difference between the oil gap and the outside of the winding changes greatly, the gas relay may misoperate.
The traversing fault current heats the winding operation. When the fault current multiple is large, the winding temperature rises quickly, which makes the volume of oil expand, resulting in the misoperation of the gas relay.
(6)Gas relay or secondary circuit failure. The above mentioned factors may cause gas protection signal action. After the light gas signal appears, the transformer should be comprehensively inspected immediately, analyzed and dealt with in time.
Processing process of transformer light gas action:
(1) Whether the oil level and oil color in the oil pillow are normal.
(2) Whether there is gas in the gas relay.
(3) Whether the transformer body and strong oil system has oil leakage phenomenon.
(4) Whether the transformer load, current and temperature are within the allowable range.
(5) Whether the transformer sound is normal.
(6) Whether the transformer is put into operation after maintenance, replenishment of oil during operation, replacement of regenerator silica gel, etc.
(7) Take out the gas of the gas relay to determine whether it is combustible gas. If necessary, do chromatographic analysis or extract oil sample for analysis.
In the process of processing, when the interval of light gas protection action becomes shorter and shorter, the standby transformer should be switched immediately and the transformer should be removed from operation.