Abnormal operation and processing method of transformer
Abnormal situation during the operation of the transformer are: the top oil temperature gauge, oil level anomalies, gas alarm relay, cooling system fault analysis and abnormal chromatography. Operators found that the transformer abnormal operation, should promptly analyze its causes, nature and impact, take appropriate measures to prevent failure to expand, to protect the safe operation of transformers.
Upper oil temperature rise
1., check the transformer load and cooling medium temperature has changed greatly, and according to the relevant technical records, and the load and cooling medium temperature should be compared to the oil temperature.
2. check whether the cooling device of the transformer is out of order, such as whether the fan, the oil pump is running properly, whether the cooling water pressure is normal or not, whether the cooling unit power is put in or switched normally.
3. check the meter and its circuit is normal. Comparing the field meter value with the remote measurement, the result of comparison should be based on the higher temperature as the basis for controlling the transformer temperature.
4., if the oil temperature is found to be higher than usual, under the same load and cooling conditions, the temperature is higher than 5~10 DEG C and continues to rise, and the cooler is running normally, the transformer has been found to be out of order, and the transformer shall be stopped immediately.
Abnormal oil level
Under normal circumstances, the oil level of the transformer varies with the temperature. The oil temperature depends on how much load the transformer carries, the ambient temperature and the operation of the cooling system. If leakage occurs in the relevant part of the transformer, the oil level will decrease accordingly. There are two kinds of abnormal oil level in transformer:
1. oil level is too high. The reason is that the transformer is affected by high temperature for a long time, it expands when heated, and makes the oil level rise. When the oil is in high oil, the transformer enters the water. When the oil level is too high, it will cause oil spill. Therefore, when the oil level is found high, the oil drain should be carried out by the maintenance personnel in time, but the oil level should be controlled at the same time as the oil temperature at that time.
2. oil level is too low. The main reasons are oil leakage of transformer, sudden decrease of transformer load or obvious decrease of ambient temperature. The forced cooling of oil circulation guiding cooling transformer leads to transformer oil seeping into water for a long time. Generally speaking, the oil level of the transformer will not leak much in a very short time. The operator shall monitor the oil level changes of the transformer at any time.
When the oil level is lower than the gas relay, the alarm will be taken. When the oil level is too low, the core winding may be directly exposed to the air and the consequences will be severe. When the oil level of the main transformer is abnormally lowered, a comprehensive check shall be made to see whether there is any oil leakage, whether or not the accident drain valve has been mistakenly opened or leaking, and promptly stopped.