Power transformer power
Power transformer power
It is well known that the function of the Power Transformer is to help transmit power, voltage conversion and insulation isolation, and thus has been widely used in power technology and power electronics technology.
The most basic type of power transformer consists of two sets of coils wound with wires and they are inductively coupled together. When an alternating current (having a certain known frequency) flows to one of the coils, an alternating voltage having the same frequency is induced in the other coil, and the magnitude of the induced voltage depends on the coupling of the two coils and the magnetic flux. The extent of the chain.
Generally, a coil connected to an AC power source is called a primary coil; and a voltage across the coil is called a primary voltage. The induced voltage in the secondary coil may be greater or less than the primary voltage, which is determined by the turns ratio of the primary coil to the secondary coil. Therefore, the power transformer is divided into two types: boost and step-down transformers. Most power transformers have a fixed core with a primary and secondary coil wound around it. Due to the high magnetic permeability of the iron, most of the magnetic flux is confined to the core, so that the two sets of coils can thereby obtain a relatively high degree of magnetic coupling.
In some transformers, the coil and the iron core are tightly coupled, and the ratio of the primary to the secondary voltage is almost the same as the coil turns ratio of the two. Therefore, the turns ratio of the transformer can generally be used as a reference for transformer boost or buck. Due to this boosting and step-down function, the transformer has become an important accessory of modern power systems. Increasing the transmission voltage makes the long-distance transmission of electricity more economical. As for the step-down transformer, it makes the power application more diversified. It can be said that if there is no transformer, the industry can not achieve the status quo of development.
Various electronic equipment is commonly used in transformers. The reason is: providing various voltage levels to ensure normal operation of the system; providing electrical isolation of parts with different potentials in the system; providing high impedance to alternating current, but providing low impedance to direct current; Maintain or modify the waveform and frequency response at different potentials. In addition to the small size of the power transformer, there is no clear dividing line between the power transformer and the electronic transformer. Generally speaking, the power supply of the 60 Hz power network is very large, and it may cover a large capacity in half a continent. The power limitation of an electronic device is usually limited by the ability to rectify, amplify, and other components of the system, some of which are amplified power, but it still falls within the scope of small power compared to the power generation capability of the power system.
Therefore, according to the size of the transmission power, the power transformer can be divided into the following several files: high power: 10kVA or more; medium power: 10kVA ~ 0.5kVA; low power: 0.5kVA ~ 25VA; micro power: 25VA or less. The transmission power is different, and the design of the power transformer is different. It should be self-evident.