What Are The Classifications Of Transformers?
(1) Power transformer
At present, the representative products that have been running in the system include: 1150KV, 1200MV·A, 735～765KV, 800MV·A, 400～500KV, 3-phase 750MV·A or single-phase 550MV·A, 220KV, 3-phase 1300MV·A power Transformer; DC transmission ±500KV, 400MV·A converter transformer. Power transformers are mainly oil-immersed, and the product structure is core-type and shell-type. The core type production volume accounts for 95%, and the shell type only accounts for 5%. The core type and the shell type have no overwhelming advantages, but the core type process is relatively simple, so it is adopted by most enterprises; while the shell type structure and process are more complicated, and only traditional factories use it. The shell type is especially suitable for high voltage and large capacity. It has advantages in insulation, machinery and heat dissipation, and is suitable for transportation of hydropower stations in mountainous areas. [3]
(2) Distribution transformer
The capacity of foreign distribution transformers can reach 2500KV·A, with round and oval core forms. The round shape accounts for the vast majority, and the oval shape has a small M0 (the pitch of the iron core column), so the material can be reduced, and the corresponding coil is an ellipse. Low-voltage coils are wire-wound and foil-type, and fuel tanks have radiator pipes (a few) and corrugated (most). [3]
(3) Dry-type transformer
Recently, dry-type transformers have been developed rapidly in China. In large cities such as Beijing, Shanghai and Shenzhen, dry-type transformers have accounted for 50%, and in other large and medium-sized cities it has also accounted for 20%. Dry change has four structures: epoxy resin pouring, filler pouring, wrapping and dipping. At present, open-ventilated H-class dry-type transformers are widely used in Europe and the United States. They are a new type of H-class dry-type transformer developed after absorbing the characteristics of the winding structure on the basis of the impregnation type and adopting Nomex paper. Not yet promoted. At present, the dry-type distribution transformer with the largest short-circuit test capacity in China is 2500KV·A, 10/0.4KV; the dry-type power transformer with the largest short-circuit test capacity is 16000KV·A, 35/10KV. [3]
(4) Amorphous alloy transformer
Although the amorphous alloy transformer has poor short-circuit resistance and high noise, it is energy-saving, so the future development prospects are considerable. At present, China’s largest manufacturer of amorphous alloy transformer cores has an annual iron core production capacity of 3000 to 4000 tons. The production technology of cores and transformers is not a key factor restricting the promotion of amorphous alloy core gold transformers. A breakthrough in amorphous alloy strips In order to promote a leap in product quality. [3]
(5) Wound core transformer
At present, the production of wound core transformers is mainly concentrated in the 10KV level, and the capacity is generally less than 800KV·A, and 1600KV·A has also been trial-produced, but the power department purchases most of the capacity below 315KV·A, which is suitable for rural power grids. There are more than 200 coiled core transformer manufacturing plants in China, 20% of which are of a certain scale. The production capacity of China's strong coil core transformer is about 16 million KV·A, but the actual output is low.
