In today's highly electrified society, power transformers, as core components in power and electronic systems, play a vital role. It is not only responsible for converting AC power of one voltage level to another voltage level, but also undertakes multiple functions such as electrical isolation and impedance matching.

A power transformer is a device that uses the principle of electromagnetic induction to change AC voltage. It mainly consists of two parts: the core and the winding. The core is the magnetic circuit part of the transformer, which is usually stacked with silicon steel sheets and pressed tightly on the insulator for current flow and heat dissipation; the winding is the circuit part of the transformer, which is wound into a ring and embedded in the core slot. The current generates a magnetic field in the core, thereby realizing voltage conversion.

When AC current passes through the primary winding of the transformer, an alternating magnetic flux is generated in the core. This alternating magnetic flux passes through the secondary winding, thereby generating an induced electromotive force in the secondary winding. The magnitude of the induced electromotive force depends on the turns ratio of the primary and secondary windings and the rate of change of the magnetic flux. By changing the turns ratio of the primary and secondary windings, the voltage can be increased or decreased.

Power transformers can be divided into many types according to their uses and structures. Among them, the most common ones include:
Power transformers: mainly used for the transmission and distribution of electric energy in power systems, such as power plants, substations, transmission lines and distribution systems.
Electronic transformers: mainly used for voltage conversion and electrical isolation in electronic equipment, such as computer power supplies, audio equipment, etc.
Special transformers: such as audio transformers, pulse transformers, etc., used for signal transmission and processing in specific occasions.
Autotransformer: has only one winding, and the voltage is increased or decreased by tapping.
Mutual inductance transformer: has two or more independent windings, and voltage conversion is achieved through electromagnetic induction.

Power transformers are widely used in power systems and electronic systems. In power systems, transformers are one of the key equipment for power transmission and distribution. They are widely used in power plants, substations, transmission lines and distribution systems to increase power from low voltage levels to high voltage levels for long-distance transmission, or to reduce high voltage levels to low voltage levels for users.

Transformers also play an important role in electronic devices. For example, in computer power supplies, transformers are used to convert the mains voltage into the low voltage required inside the computer; in audio equipment, transformers are used for audio signal transmission and impedance matching. In some special occasions, such as medical equipment and railway systems, transformers also have unique application value.

Selecting a power transformer suitable for a specific application requires consideration of multiple factors, including electrical parameters (such as input voltage, output voltage, power capacity, etc.), performance requirements (such as efficiency, stability, reliability, etc.), environmental factors (such as operating temperature, heat dissipation conditions, protection level, etc.) and other considerations (such as size, installation method, cost and cost performance, etc.).

In order to ensure the normal operation of the power transformer and extend its service life, regular maintenance and care are also required. This includes regular inspection of the appearance and structure of the transformer, monitoring its operating status, cleaning dust and debris, etc. When the transformer fails, it should be repaired or replaced in time to ensure the stable operation of the power system.