In the operation of power transformation and distribution, transformers are indispensable. It is very necessary to be familiar with and master the basic knowledge of transformers. The basic knowledge reserve of transformers is an essential skill for every electrician!
What is a transformer?
In the AC circuit, the equipment that raises or lowers the voltage is called a transformer. The transformer can transform any value of voltage into the voltage value we need with the same frequency to meet the requirements of electric energy transmission, distribution, and use.
For example, the electricity from a power plant has a lower voltage level, and the voltage must be increased before it can be transported to a distant electricity area. The electricity area must be reduced to a suitable voltage level to supply power equipment and daily electricity. Equipment.
How does the transformer transform the voltage?
The transformer is made based on electromagnetic induction. It consists of an iron core laminated with silicon steel sheets (or silicon steel sheets) and two sets of coils wound on the iron core. The iron core and the coils are insulated from each other without any electrical connection.
The coil connecting the transformer and the power supply side is called the primary coil (or primary side), and the coil connecting the transformer and the electrical equipment is called the secondary coil (or secondary side). When the primary coil of the transformer is connected to an AC power source, changing magnetic lines of force will be generated in the iron core.
Since the secondary coil is wound on the same iron core, the magnetic field line cuts the secondary coil, the induced electromotive force will inevitably be generated on the secondary coil, causing the voltage to appear at both ends of the coil. Because the lines of magnetic force are alternating, the voltage of the secondary coil is also alternating. And the frequency is exactly the same as the power frequency.
It has been proved by the theory that the voltage ratio between the primary coil and the secondary coil of the transformer is related to the ratio of the turns of the primary coil and the secondary coil, which can be expressed by the following formula: primary coil voltage/secondary coil voltage=primary coil turns/secondary coil turns It shows that the more turns, the higher the voltage. Therefore, it can be seen that the secondary coil is less than the primary coil, which is a step-down transformer. The opposite is a step-up transformer.
What are the types of transformer design?
According to the number of phases, there are single-phase and three-phase transformers
According to the purpose, there are power transformers, special power transformers, voltage regulating transformers, measuring transformers (voltage transformers, current transformers), small power transformers (for small power equipment), and safety transformers.
According to the structure, there are two types: core type and shell type. The coil has double winding and multi winding, autotransformer.
According to the cooling method, there are oil-immersed and air-cooled.
What are the components of the transformer components?
Transformer components are mainly composed of iron core and coil, in addition to fuel tanks, oil pillows, insulating sleeves, and tap openings.