What material is the oil immersed transformer winding?

There are many internal structures of oil-immersed transformers, and the functions of various structures are also more. If you want to know more about the internal structure of oil-immersed transformers, it is necessary to carry out various structures of oil-immersed transformers. To understand, the winding of the oil-immersed transformer is an important part of the oil-immersed transformer. It can adjust the voltage and current of the oil-immersed transformer, making the current and voltage of the oil-immersed transformer more stable. What material are the windings of common oil-immersed transformers? How to identify them?

There are several ways to identify the material of oil-immersed transformer windings:

1. Compared with the weight, the aluminum oil-immersed transformer of the same capacity is lighter in weight.

2. Compared with the volume, the aluminum oil-immersed transformer of the same capacity has a larger volume.

3. Look at the nameplate. The products of regular manufacturers are produced according to the standard. The copper wire oil-immersed transformer should be marked with S7, S9, S11, etc., while the aluminum wire oil-immersed transformer should be marked with SL7 and SL9; L is the aluminum winding.

4. Measure the DC resistance of the winding:

(1) According to the formula R1/R2=(x+T1)/(x+T2) where: T1, T2 are two temperatures (units are degrees Celsius); R1, R2 are the DC resistance at T1, T2, respectively, to solve the equation You know, theoretically, copper is 235, and aluminum is 225.

(2) To know the cross-sectional area and total length of the copper wire in the oil-immersed transformer, you can ask the manufacturer. Use a meter to measure the resistance at both ends of the winding, and calculate the resistivity according to resistance = length × resistivity ÷ cross-sectional area. Then compare it with the resistivity of pure copper. If the difference is very large, it means that it is not pure copper wire.

5. For the identification of the copper-aluminum hybrid winding, the core-lifting inspection can be carried out. By checking the resistance value on the coil and the joint form, it is judged that the copper-aluminum joint is over-wired at the terminal of the aluminum wire oil-immersed transformer.