S11-M Series Oil-Immersed Transformer (30~6300 kVA / 10 kV) | Energy-Efficient and Reliable Power So

The S11-M Series Oil-Immersed Transformer is designed for high efficiency, reliability, and long operational life in medium-voltage power distribution networks. With a capacity range from 30 kVA to 6300 kVA and a rated voltage of 10 kV, this transformer is widely used in industrial facilities, commercial complexes, residential areas, and utility substations.

Using high-quality cold-rolled silicon steel and advanced winding technology, the S11-M transformer achieves lower no-load loss and reduced noise compared with traditional designs. Its optimized magnetic circuit structure ensures stable operation, low temperature rise, and high overload capacity, providing reliable performance even in demanding environments.

The sealed tank structure prevents moisture ingress, enhancing insulation reliability and minimizing maintenance. Fully compliant with IEC 60076, GB 1094, and ANSI C57 standards, this transformer offers superior durability and energy efficiency for long-term operation.

Structure and Working Principle of Oil-Immersed Transformer

An oil-immersed transformer consists primarily of three main components: the core, the winding, and the bushing. The core provides a magnetic path, while the winding—made of insulated conductor coils—creates the magnetic field. The insulation thickness of the winding increases with voltage level, ensuring safety and reliability. The bushing connects the internal windings to external power systems such as substations.

In an oil-immersed transformer, the core and coils are completely submerged in insulating oil, which performs dual functions: cooling and electrical insulation. The oil circulates naturally through convection, transferring heat from the windings to the outer tank walls or air-cooled radiators. This process keeps the internal temperature within safe limits, extending the transformer's lifespan.

Purpose and Advantages

Oil-immersed transformers can be installed on ground pads, poles, or pedestals for outdoor and indoor applications. They are widely used in power transmission and distribution networks, renewable energy plants, and small industrial facilities. With high load capacity and excellent heat dissipation, they help reduce power losses, lower energy consumption, and minimize user costs.

The oil not only enhances insulation performance but also improves cooling efficiency and the durability of internal components. This results in long service life and stable electrical performance under continuous operation.

Product Features

+ The three-phase oil-immersed transformer adopts a new insulation structure to improve short-circuit withstand capability.
+ The core is made of high-quality cold-rolled silicon steel sheets, ensuring low magnetic loss and low noise.
+ The winding uses multilayer cylindrical or foil structures with special anti-loosening fasteners.
+ High efficiency and low loss design significantly reduces energy consumption and operating costs.
+ Fully sealed tank structure prevents oil leakage and moisture penetration.
+ Recognized as a national high-tech and energy-saving product.

Implementation Standards

• GB/T 6451-2015: Oil-immersed power transformer technical parameters and requirements
• GB 1094.1-2013: Power transformers – Part 1: General rules
• GB 1094.2-2013: Power transformers – Part 2: Temperature rise of liquid-immersed transformers
• GB 1094.5-2008: Power transformers – Part 5: Ability to withstand short circuit
• GB/T 1094.7-2008: Power transformers – Part 7: Loading guide for oil-immersed transformers

Regular Service Conditions

a) Altitude: below 1000 m above sea level
b) Ambient temperature: within the range below
c) Maximum ambient temperature: +40°C
d) Maximum daily average temperature: +20°C
e) Minimum outdoor ambient temperature: -25°C

Applications

S11-M Series Oil-Immersed Transformers are ideal for use in industrial plants, commercial buildings, residential power distribution systems, renewable energy facilities, and public utility substations. They provide energy-efficient, low-noise, and reliable operation for modern electrical networks.

Performance parameters