Transformers Everywhere, Do You Know What They Do?

Our life is inseparable from electricity, ranging from "West-to-East electricity transmission" and "North-South mutual supply", to small air conditioners that can heat and cool the wall, refrigerators to prevent food spoilage, etc. These modern electrical appliances all require the supply of electricity.

Rapidly growing demand for electricity has led to transformers everywhere.

Transformers are often found on electric poles in the streets and alleys, and the box will be marked with the warning words "High Voltage Danger, Do Not Approach".

What is the function of the transformer? As the name implies, its main function is to transform the voltage, increasing or decreasing the voltage, so as to ensure normal electricity consumption. The following will give you a detailed introduction to the "big hero" in life - the transformer.

First, the composition of the transformer

The most basic parts of a transformer are the coil and the iron core.

The coils can be divided into primary coils and secondary coils. The distinction between the two is whether the coil is connected to the power supply. The coil connected to the power supply is called the primary coil, and the rest of the coils are the secondary coils.

The role of the transformer coil is to transform the AC voltage, current and impedance. The role of the iron core is to strengthen the connection between the two coils. In most cases, in order to reduce the eddy current and hysteresis loss in the iron, the iron core is often made of lamination of painted silicon steel sheets.

Second, the classification of transformers

1. Classification by use: It can be divided into three categories, electric transformer, power transformers and special transformers.

Electric transformer, often used in televisions, radios, etc., belong to the category of low-voltage electricity.

Power transformers are generally more than 10kv lines, and its main function is to step down, that is, to reduce the voltage to the voltage used at all levels to meet the needs of electricity everywhere.

Special transformers are not very common in daily life, and their main application sites are factories, which are used in places with special requirements such as dustproof, heat resistance and moisture resistance.

2. Classification by cooling medium: common ones are dry-type transformers, liquid (oil) immersed transformers and inflatable transformers.

In daily life, dry-type transformers and oil-immersed transformers are often confused. In fact, the two can be simply distinguished from the appearance and the site.

In terms of appearance, dry-type transformers can directly see the iron core and coil, while oil-type transformers can only see the outer shell of the transformer.

From the point of view of the use site, dry-type transformers are mostly used in places that require "fire protection" and "explosion-proof", and are generally used in large buildings and high-rise buildings, while oil-type transformers have a high probability of oil ejection or leakage after failure. It is easy to cause fire, so it is mostly used outdoors, and the place where the "accident oil pool" is dug.

In addition, the capacity of oil-immersed transformers is larger than that of dry-type transformers, but under the same capacity, the price of dry-type transformers is higher than that of oil-immersed transformers.

Dry-type transformer models generally start with SC (epoxy cast encapsulation), SCR (non-epoxy cast solid insulation encapsulation) or SG (open).

There are many classification methods and types of transformers. For example, according to the cooling method, they can be divided into natural cooling, air cooling and water cooling. According to the number of coils, it can be divided into autotransformers, two-winding and three-winding transformers. If classified according to the core type, there are core transformers, shell transformers and so on.