The structure of a dry-type transformer is intricately designed around the requirements of thermal dissipation efficiency, structural compactness, and safety protection. Its core structure can be divided into four main parts: the iron core, windings, enclosure, and auxiliary components, all of which work in tandem to ensure efficient operation and safety protection. Below is a detailed structural analysis:

　　Iron Core

　　Function: The iron core serves as the primary magnetic circuit of the dry-type transformer, primarily functioning to conduct magnetism. It transforms electrical energy from the primary circuit into magnetic energy and then back into electrical energy in the secondary circuit. Additionally, the iron core acts as the mechanical framework of the transformer, supporting the leads and housing nearly all internal components.

　　Material: The iron core is typically made of silicon steel sheets with high silicon content and high resistivity to minimize eddy current losses. The silicon steel sheets are first cut into the required shapes and sizes and then assembled in an interleaved manner.

　　Structure: The iron core consists of two parts: the core limb and the yoke. The core limb is fitted with windings, while the yoke serves to close the magnetic circuit. The iron core structure can be classified into two types: core-type and shell-type, with the main difference lying in the distribution of the magnetic circuit.

　　Windings

　　Function: The windings constitute the electrical circuit of the dry-type transformer, establishing a magnetic field and transmitting electrical energy. They are generally wound from copper or aluminum wires wrapped in insulating paper and fitted over the core limbs of the transformer.

　　Structure: Winding structures can be classified into two types: layer-type and disc-type. The layer-type structure involves arranging the wire turns continuously along the axial direction of the winding, while the disc-type structure involves winding the wire turns radially to form a disc (segment), which are then stacked axially to form the complete winding. In China, most power transformers produced adopt a concentric winding structure, where the high-voltage and low-voltage windings are coaxially sleeved over the core limb in a cylindrical shape.

　　Insulation: The windings of dry-type transformers often employ epoxy resin casting or glass fiber-reinforced epoxy resin casting for insulation to enhance insulating performance and mechanical strength.

　　Enclosure

　　Function: The enclosure primarily serves to protect the internal components of the transformer, preventing users from directly contacting live parts and shielding the transformer from external influences such as solid foreign objects and water.

　　Material: The enclosure is typically made of metal materials such as steel plate or aluminum alloy. The steel plate surface is treated with anti-corrosion paint to enhance its corrosion resistance.

　　Protection Level: The enclosure usually meets an IP23 rating or higher, with some models reaching as high as IP54. This indicates that the enclosure can prevent the entry of solid foreign objects with a diameter ≥12.5mm and is resistant to water splashes or sprays.

　　Structure: The enclosure mainly consists of the enclosure body, enclosure cover, enclosure base, and enclosure connectors. The enclosure body is the main part, the enclosure cover provides protection, the enclosure base serves as the support, and the enclosure connectors are used to join the various parts together.

　　Auxiliary Components

　　Fan: Used for forced air cooling to enhance the thermal dissipation efficiency of the transformer. The fan can be activated during overload operation to reduce temperature rise.

　　Temperature Controller: Used to monitor the temperatures of the windings and iron core in real-time and trigger alarms or trip protections when temperatures exceed preset values.

　　Temperature Display: Used to display temperature information of the transformer, facilitating users in understanding the operational status of the transformer.

　　On-Load Tap Changer: Used to switch tap positions under load conditions to change the voltage ratio and stabilize the low-voltage output voltage.