What is an oil-immersed transformer?

Oil-immersed transformers are power equipment that utilizes insulating oil as both the insulating and cooling medium; they are widely used in power transmission and distribution systems, industrial parks, commercial buildings, new energy projects, and infrastructure construction. Characterized by operational reliability, excellent heat dissipation, strong overload capacity, and a long service life, oil-immersed transformers have become one of the most common types of power distribution equipment in global power systems.

Oil-immersed transformers primarily consist of an iron core, windings, an oil tank, insulating oil, radiators, and protective devices. During operation, electrical energy enters via the high-voltage side and is converted—through the principle of electromagnetic induction—into low-voltage energy suitable for end-user consumption. The insulating oil not only provides superior insulation but also effectively dissipates heat generated during operation, thereby ensuring the transformer's long-term, stable performance.

Based on loss levels and structural characteristics, oil-immersed transformers are categorized into various series, such as S11, S13, S20, S22, and the SH15 amorphous alloy transformer. Among these, the S11 series is known for stable operation and cost-effectiveness; the S13 series offers lower losses and higher efficiency; the S20 and S22 series represent a new generation of energy-saving products; and the SH15 amorphous alloy transformer utilizes an amorphous alloy core to significantly reduce no-load losses and enhance energy utilization efficiency.

Compared to dry-type transformers, oil-immersed transformers offer advantages such as superior heat dissipation, a wide capacity range, lower operating costs, and robust overload capabilities. Consequently, they are extensively deployed in factories, residential complexes, commercial complexes, power distribution systems, and new energy projects. These products support various voltage ratings—including 10kV, 11kV, 13.8kV, 20kV, 33kV, and 35kV—and can be customized with specific capacities and configurations to meet individual customer requirements.

Driven by the expansion of global power infrastructure and the growth of the new energy sector, high-efficiency, energy-saving oil-immersed transformers are attracting increasing attention from users. By incorporating high-quality silicon steel sheets, all-copper windings, and advanced manufacturing processes, modern oil-immersed transformers effectively reduce operating losses and improve energy efficiency while ensuring reliable power supply. As a professional transformer manufacturer, we offer S11-M, S13-M, S20-M, S22-M, and SH15 amorphous alloy oil-immersed transformers. We support customization across various voltage ratings and capacities, effectively meeting power distribution needs in the industrial, electric power, construction, and new energy sectors.