What is a electrical distribution transformer?
A electrical distribution transformer is a common electrical device that can be used to convert an alternating voltage of a certain value into an alternating voltage of another value of the same frequency, and can also change the value of the alternating current, transform the impedance or change the phase.
The meaning of electrical distribution transformer
The power plant wants to transmit the electric power of P=3UIcosφ to the area where the electricity is used. When P and cosφ are a certain value, if the voltage used is higher, the current in the transmission line is smaller, so the loss on the transmission line can be reduced. Save conductive material. Therefore, it is the most economical to use high voltage for long-distance power transmission.
At present, the voltage of AC transmission in my country has reached a maximum of 500kV. Such a high voltage is not allowed to be directly produced by the generator, either from the aspect of safe operation of the generator or from the aspect of manufacturing cost. The output voltage of the generator is generally 3.15kV, 6.3kV, 10.5kV, 15.75kV, etc. Therefore, a step-up transformer must be used to increase the voltage before long-distance transmission.
After the electric energy is delivered to the power-consuming area, in order to meet the voltage requirements of the electrical equipment, it is necessary to use transformers at all levels of substations to reduce the voltage to the voltage value required by various electrical appliances.
In terms of electricity consumption, the voltage required by most electrical appliances is 380V, 220V or 36V, and a few motors also use 3kV, 6kV, etc.
Electrical Distribution Transformer Classification
According to their different uses, there are power transformers, power transformers, voltage regulating transformers, instrument transformers, and isolation transformers. According to the structure, it is divided into two-winding transformer, three-winding transformer, multi-winding transformer and autotransformer. According to the core structure, it is divided into shell-type transformers and core-type transformers. According to the number of phases, it is divided into single-phase transformers, three-phase transformers and multi-phase transformers. Although there are many types of transformers, the basic principle and structure are the same.
The Basic Structure Of a Electrical Distribution Transformer
(1) Iron core
The transformer is composed of two or more coils (windings) set on a closed iron core,
The core and the coil are the basic components of the transformer. The iron core forms the magnetic circuit required for electromagnetic induction. In order to reduce the eddy current loss caused by the change of the magnetic flux, the iron core of the transformer should be stacked with silicon steel sheets with a thickness of 0.35 to 0.5 mm. The sheets are separated by insulating paint. The iron core is divided into two types: the core type and the guest type.
(2) Coil
The coil connected to the transformer and the power supply is called the primary winding (or the primary side, or the primary winding), and its number of turns is N 1 , and the coil connected to the load is called the secondary winding (or the secondary side, or the secondary winding), and the number of turns is is N 2 . The windings and the windings and the windings and the core are insulated from each other.
Transformers are used in almost all electronic products. Its principle is simple, but the winding process of transformers will have different requirements according to different applications (different uses). The functions of the transformer mainly include: voltage transformation; impedance transformation; isolation.
