November 6, 2025
Transformer manufacturers note that transformers come in a wide array of types, which can be classified based on various criteria such as application, structure, phase number, cooling methods, and more.
By Application: Transformers can be categorized into power transformers and special transformers. Special transformers include furnace transformers, rectifier transformers, power frequency test transformers, voltage regulators, mine transformers, audio transformers, medium-frequency transformers, high-frequency transformers, impact transformers, instrument transformers, electronic transformers, reactors, and others.
By Structure: Based on their structural design, transformers can be classified as double-winding transformers, three-winding transformers, multi-winding transformers, and autotransformers.
By Cooling Method: Transformers are also differentiated by their cooling techniques, falling into two primary categories: oil-immersed transformers and dry-type transformers.
Further Cooling Method Classification: Within the oil-immersed and dry-type categories, transformers can be further classified by specific cooling methods such as natural cooling, air cooling, water cooling, forced oil circulation air (or water) cooling, among others.
By Core or Coil Structure: Transformers can be classified according to the design of their core or coil, including core transformers (with insert cores, C cores, or ferrite cores), shell transformers (also with insert cores, C cores, or ferrite cores), ring transformers, metal foil transformers, and radiant transformers.
By Power Supply Phase Number: Transformers can be single-phase, three-phase, or multi-phase, depending on the number of power supply phases they are designed to handle.
By Conductive Material: Based on the conductive material used, transformers can be classified as copper wire transformers, aluminum wire transformers, half-copper half-aluminum transformers, and superconducting transformers.
By Voltage Regulation: Transformers can be divided into no-load voltage regulating transformers and on-load voltage regulating transformers, depending on their voltage regulation capabilities.
By Neutral Insulation Level: Transformers can be classified as full insulation transformers or half insulation (also known as classified insulation) transformers, based on the level of insulation provided at the neutral point.
The core and winding are the fundamental components of a transformer, forming its main body. Here, we will introduce the structures of two common types of transformers: the three-phase oil-immersed power transformer and the three-phase epoxy resin-insulated coherent power transformer.
Three-Phase Oil-Immersed Power Transformer: This type of transformer features a core and windings that are immersed in insulating oil, which serves both as an electrical insulator and a cooling medium. The core is typically constructed from laminated steel sheets to reduce eddy current losses, while the windings are made of copper or aluminum conductors wound around the core. The entire assembly is housed in a tank filled with insulating oil, which helps dissipate heat generated during operation.
Three-Phase Epoxy Resin-Insulated Coherent Power Transformer: In contrast to the oil-immersed type, this transformer uses epoxy resin as the primary insulating material. The core and windings are encapsulated in epoxy resin, providing excellent electrical insulation and mechanical protection. This design eliminates the need for insulating oil, making the transformer more compact and environmentally friendly. The epoxy resin also enhances the transformer's resistance to moisture, dust, and chemicals, extending its service life.
In summary, transformers are versatile electrical devices that come in various types and structures, each designed to meet specific application requirements. Understanding their classification and structure is essential for selecting the right transformer for a given task and ensuring its reliable and efficient operation. We are a professional electric furnace manufacturer. For further inquiries, or if you require submerged arc furnaces, electric arc furnaces, ladle refining furnaces, or other melting equipment, please do not hesitate to contact us at susan@aeaxa.com
