The appearance of the oil-immersed transformer has been improved, the price is conscientious, the energy saving is significant, the magnetic circuit is uniform, the no-load loss is low, the noise is low, the temperature rise is low, maintenance-free, high efficiency, and small size. These improvements will enable oil-immersed transformer manufacturers to better serve customers.
Ⅰ. The scope of use of oil-immersed transformers
The oil immersed type transformers are suitable for many fields, such as subways, drilling platforms, railway stations, high-rise buildings, commercial blocks, airports, industrial and mining enterprises, and oil production platforms.
It is especially suitable for use in places with high fire protection requirements and harsh environments such as flammable and explosive. Oil-immersed transformers can also be used in residential areas, commercial streets, industrial and mining enterprises and rural power and lighting purposes.
Ⅱ. Structure of oil-immersed transformer
High-quality material-grain is widely used, iron core material of cold-rolled silicon steel sheet, full oblique non-porous binding process structure, iron core is multi-step ladder shape, three-joint or five-joint, low air loss and low noise.
The iron core is directly wound with special equipment, with no joints and no corner weight, reducing magnetic resistance and low air loss; compared with traditional silicon steel sheet, oil-immersed transformer iron core reduces air loss by 72% on average, and The load current is reduced by half.
Coil: It is made of high-quality acetal enameled round copper wire, flat copper coin or copper knot drawn from oxygen-free copper rod, and its forms include cylindrical, continuous, new spiral, split, etc., with sufficient The electrical strength, mechanical strength and heat dissipation capacity.
Oil tank: It is made of high-quality steel plates by electric welding. The oil-immersed transformer oil tank has oval, rectangular and other structures, and the heat dissipation element adopts chip radiator, expansion radiator or corrugated oil tank.
The fuel tank undergoes a reliable sealing test in the factory. After the inner and outer surfaces are treated with pickling, etc., the three bottoms and one side are painted with paint, which is both anti-corrosion and beautiful.
Ⅲ. Performance characteristics of oil-immersed transformers
1. The iron core is made of high-permeability oriented silicon steel sheet, with a three-order full bevel joint structure, and the surface of the iron core is covered with protective epoxy resin to prevent moisture and rust.
2. The low-voltage winding generally adopts a cylindrical structure wound with copper foil except for the small-capacity copper wire; the high-voltage winding of the oil-immersed transformer adopts a segmented multi-layer cylindrical structure, so that the ampere-turn distribution of the winding is balanced and leakage is avoided. Small magnetism, high mechanical strength, and strong short-circuit resistance.
3. The equipped low-noise air-cooling device automatically measures the temperature and controls the start and stop of the fan, which can increase the capacity of the transformer by 40%.
4. Through the temperature sensing element and sensing system embedded in the low-voltage winding, the fan is started, turned off and tripped according to the set value, so as to protect the oil-immersed transformer.
5. The transformer is equipped with stainless steel casing, and the protection level reaches IP20 and IP23. IP20 can prevent solid conductors with a diameter greater than 12mm from entering the shell; IP23 can also prevent water droplets from entering an angle of 60°C from the vertical line. It can prevent short circuits and dangerous accidents.
Ⅳ. The normal operating conditions of oil-immersed transformers
The altitude does not exceed 1000m, the maximum temperature is 40℃; the maximum daily average temperature is 30℃; the maximum annual average temperature is 20℃; the minimum temperature is -25℃ (for outdoor type); the minimum temperature is -5℃ (for indoor type).
Because oil-immersed transformer manufacturers have the above characteristics, they are widely used in power transmission systems, such as hotels, restaurants, airports, high-rise buildings, commercial blocks, residential quarters and other important places; as well as subways, smelters, ships, offshore drilling platforms and other places with harsh environments.
