Function and principle of transformer

Transformer is a kind of electrical equipment used for power conversion, and is an indispensable and important device in the power grid. It can convert the AC power of one voltage and current into the AC power of another voltage and current of the same frequency. Almost all electronic products use transformers. Its principle is very simple, but the winding process of transformer will have different requirements according to different applications (different purposes). The functions of transformer mainly include: voltage conversion; Impedance transformation; Isolation, voltage stabilization (magnetic saturation transformer), etc. The common core shapes of transformers are generally E-type and C-type cores. Transformers In different environments, transformers have different uses, such as:

1. Increasing the voltage during long-distance transmission can reduce the power loss on the line.

2. When reaching the use area, reduce the voltage to meet the power demand of different users.

3. During impedance matching, the transformer connection can change the impedance.

4. Isolation transformer can be used to isolate the two phases to prevent electric shock accidents.

Common transformers can be divided into the following categories:

1. By phase number:

1) Single-phase transformer: used for single-phase load and three-phase transformer group.

2) Three-phase transformer: used for the step-up and step-down of three-phase system.

2. According to cooling mode:

1) Dry-type transformer: It relies on air convection for natural cooling or fan cooling, and is mainly used for small capacity transformers such as high-rise buildings, high-speed toll stations, local lighting, electronic circuits, etc.

2) Oil-immersed transformer: rely on oil as cooling medium, such as oil-immersed self-cooling, oil-immersed air-cooling, oil-immersed cooling, forced oil circulation, etc.