Transformer is a device that uses the principle of electromagnetic induction to alter alternating voltage, primarily consisting of the primary coil, secondary coil, and core (magnetic core). Its main functions include voltage transformation, current transformation, impedance transformation, isolation, and voltage stabilization (magnetic saturation transformer).

Transformers can be categorized by their applications as follows: distribution transformers, power transformers, fully sealed transformers, modular transformers, dry-type transformers, oil-immersed transformers, single-phase transformers, electric furnace transformers, rectifier transformers, reactors, anti-interference transformers, lightning protection transformers, cabinet transformers, test transformers, corner transformers, high current transformers, excitation transformers, etc.

Transformers are fundamental equipment for power transmission and distribution, widely used in industries, agriculture, transportation, urban communities, and more. There are approximately 17 million transformers in operation in our country, with a total capacity of about 11 billion kilovolt-amperes. Transformer losses account for about 40% of the total power losses in transmission and distribution, presenting significant potential for energy savings.