Oil Immersed Self Cooled Transformer

The oil immersed self cooled transformer utilizes oil as its cooling medium. It relies on natural oil convection to carry away the heat generated by the core and coils. This type of transformer does not require additional cooling equipment and has the advantages of simple structure and easy maintenance.

Core is made of stacked high-permeability silicon steel sheets to reduce eddy current losses.

Windings are wound with copper or aluminum wires, divided into high-voltage and low-voltage sides, with insulation layers designed to withstand oil temperature changes.

Sealed Oil Tank, with a conservator, regulates the expansion of oil volume, often equipped with a breather.

Radiators enhance cooling efficiency by increasing the heat dissipation area, without the need for external power devices.

The oil immersed self cooled transformer operates based on Faraday's law of electromagnetic induction. When an alternating current flows through the primary winding, it generates an alternating magnetic field. The change in magnetic flux in the core induces a voltage in the secondary winding.

QC-passed 2500kVA 10/0.4kV oil immersed self cooled transformer is moving to shipping area for final inspection and packaging.

Heat transfer path: Core and windings generate heat → insulating oil heats up and convects → heat transferred to the oil tank wall → heat exchanged with air through radiators.

Oil circulation: Hot oil, being less dense, naturally rises, while cooler oil sinks, forming a circulation. The temperature difference is generally controlled within 55K (per GB 1094.2).

Our transformers are shipped as scheduled

High reliability: No mechanical cooling components, leading to low failure rates, designed for 25-30 years of reliable operation.

Low cost: Save 15–20% maintenance costs compared with forced oil cooled transformers (data source: IEEE C57.12.00).

Wide application: Suitable for various outdoor environments, particularly for remote areas or locations where stable power supply is unavailable.