Modern industrial enterprises widely use electricity as energy, and the electricity generated by power plants often needs to be transmitted over long distances to reach the electricity consuming areas. When the transmission power is constant, the higher the transmission voltage, the smaller the required current. Because the voltage drop is proportional to the current. The line loss is proportional to the square of the current, so using a higher transmission voltage can achieve lower line voltage drop and line loss. To manufacture a generator with a high voltage, current technology is difficult, so specialized equipment is needed to raise the voltage at the generator end and then transmit it out. This specialized equipment is called a transformer. On the other hand, a step-down transformer must be used at the receiving end to lower the high voltage to the voltage of the distribution system, so a series of distribution transformers must be used to lower the high voltage to a suitable value for use.
As can be seen from the above, a transformer is a static induction device that transmits AC electrical energy by changing the voltage. In the power system, transformers play a very important role. They not only require a large quantity, but also have good performance and reliable operation.
Transformers are not only used in power systems, but also in industrial and mining enterprises that require special power sources. For example: electric furnace transformers for smelting, rectifier transformers for electrolysis or chemical engineering, welding transformers for welding, test transformers for testing, traction transformers for transportation, compensation reactors, arc suppression coils for protection, measurement transformers, etc.
Classification of Transformers:
1> Classified by purpose: there are power transformers, special transformers (electric furnace transformers, rectifier transformers, power frequency test transformers, voltage regulators, mining transformers, impulse transformers, reactors, transformers, etc.).
2> Classified by structural type: there are single transformer, three-phase transformer, and multiphase transformer.
3> Classified by cooling medium: there are dry-type transformers, liquid (oil) immersed transformers, and gas filled transformers.
4> Classified by cooling methods: there are natural cooling, air cooling, water cooling, forced oil circulation air (water) cooling, and water internal cooling.
5> Classified by the number of coils: there are autotransformers, double winding and triple winding transformers, etc.
6> Classified by conductive materials: there are copper wire transformers, aluminum wire transformers, and semi copper and semi aluminum, superconducting transformers, etc.
7> Classified by voltage regulation method: it can be divided into non excitation voltage regulating transformers and on load voltage regulating transformers.
8> Classified by neutral insulation level: there are fully insulated transformers and semi insulated (graded insulation) transformers.
9> Classified by iron core type: core type transformers, shell type transformers, and radiation type transformers, etc.