Focus on solving DC power solutions

1. The content of regular test of power transformer includes:

①. Oil sample testing-performance indicators such as withstand voltage and impurities are carried out once every three years, and the cycle can be shortened for long-term full load or overload operation of the transformer.

② The high and low voltage insulation resistance is not less than 70% (10MΩ) of the original factory value, and the DC resistance of the winding at the same temperature, the difference between the three-phase average value should not be greater than 2%, and it is not compared with the result of the previous measurement. Should be greater than 2%.

③ The grounding resistance of the transformer is measured once every two years.

④ The cycle of cleaning and inspection after power failure is determined according to the surrounding environment and load conditions, generally once every six months to a year;

The main contents include the removal of defects found during inspections, cleaning of the porcelain casing, replacement of cracked or aging rubber pads, inspection and tightening of connection points, oil shortage and replenishment, inspection and replacement of respirator silica gel, etc.

2. The daily maintenance methods are:

① Grounding of power transformer

② The housing of the transformer should be grounded reliably, the working neutral wire and the neutral grounding wire should be laid separately, and the working neutral wire should not be buried in the ground.

③ The neutral ground loop of the transformer should be made of detachable connecting bolts near the transformer. Bus processing machine

④ The grounding of transformers equipped with valve arresters should meet the requirements of the trinity; that is, the neutral point of the transformer, the transformer shell, and the grounding of the arrester should be connected at one place and grounded together.

⑤ The grounding resistance should be less than 4 ohms.