In the long-term operation of transformer oil, it is constantly affected by electric field, high temperature and humid gas. Insulating oil will be polluted to varying degrees, and its oil quality will gradually become unqualified. When power electricity is in strong demand, it is often difficult to get a chance for oil change or power outage for oil regeneration especially. Sometimes, it will threaten safe operation.
In this case, the method of ONLINE TRANSFORMER OIL PROCESSING (i.e. transformer oil filtration or regeneration) can be used, and practice has proved that the treatment effect is very satisfactory. It can not only make the quality of the processed oil qualified, but also eliminate the unsafe phenomenon.
The precautions for online oil processing are as follows:
1) Observe the safety regulations to ensure safety during the process of online transformer oil processing;
2) The housing of all equipment must be firmly grounded;
3) When processing transformer oil online, the gas protection relay should be withdrawn from the heavy gas protection (exit the trip circuit), and only the signal circuit should be connected. To choose a good oil import and export location.
a) Prevent the dead angle caused by the oil flow;
b) Avoid washing up the sediment;
c) Control the flow rate of the oil to prevent the oil flow from being charged.
Generally, the oil is drained from the lower throttle, and the oil is returned from the upper anti-riot tube (or oil pillow). Note that when using the oil pillow breathing tube to return oil, the oil pillow must have another air hole. (For transformers with capsule sealing, the capsule sealing should be temporarily released, and the return oil should not be injected into the capsule.)
Only when it is confirmed that there is no sediment at the bottom of the tank, the oil can be returned from the lower port. If it is a transformer with forced oil circulation, the oil can be pumped from the upper anti-riot cylinder (or oil pillow), and the oil can be returned from the lower throttle. The advantage is that the oil circulation is not affected, and a higher oil temperature can be obtained, which is beneficial to oil processing.
4) After the operation mode is selected according to the purpose of oil treatment, live treatment can be carried out, and the treatment system is shown in the figure.
i. If the pH and acid value are qualified and no regeneration is required, the regeneration tank is not needed, and only remove impurities, moisture and gas.
ii. An oil filter press can be connected in series with the transformer and the vacuum oil purifier according to actual needs (such as when there are too many impurities).
iii.The transformer oil temperature generally meets the requirements during operation, and the heating may not be turned on.
5) Generally, the vacuum degree should be kept at the highest value without adjustment;
6) Pay attention to the oil level of the transformer, it should not be lower than the lower limit, if it is not enough, you can add oil;
7) Do not perform online oil processing or regeneration during thunderstorms or extreme weather;
8) Oil Sampling and transformer oil test on time according to estimates during oil processing, and oil processing can be stopped when the required indicators are reached;
9) Carrying out the work of online oil processing, no less than 2 specially trained staff shall be responsible for it;
10) Before online oil treatment, the Oil Purifier and related pipelines and equipment should be flushed clean, and the joints should be tight and the equipment should be grounded reliably.
11) When working with electric insulating oil, strictly abide by the "safe distance between the human body and the live body" of the electrical safety work regulations, such as:
- 3~10 kV ≥0.70m
- 66~110 kV ≥1.50m
- 220 kV ≥3.00m
If it is less than the above safety distance, reliable insulation measures must be adopted. During operation, the human body should not directly touch the insulator.
12) Before starting the oil filter, all water and impurities in the dirt accumulation chamber at the bottom of the oil pillow should be drained.
Note: However, it is better not to do online oil treatment if the power outage is allowed, to ensure the safe operation of oil treatment or oil regeneration after power outage.
Add：1 Xinmao Road, Beibei district, Chongqing, China