Home > News > Content
Historical Review Of The Development Of Magnetic Guiding System
- Nov 07, 2017 -

Transformer manufacturing has been 117 years since the successful development of the world's first single-phase transformer with closed magnetic circuit at the Gangts plant in Hungary in 1885. The first transformer is the use of general carbon steel wire as the core of the magnetic material, the wire wound into a core structure, wound around the core in the coil. Although this transformer can convey electric energy, but the loss is bigger, the transmission efficiency is very low. Due to the influence of insulation materials, the earliest distribution transformers are all dry-type ones with low voltage and small capacity.

Hot-rolled silicon steel appeared in the world in 1903, so the core structure was changed to laminated type. At that time, the no-load loss was more than 50% lower than that of wire as the magnetic conductive material, but the absolute value was still very large. China is in the 1940s development of transformer production. At that time, sheet metal hot-rolled silicon steel sheet as the core of the magnetic material, the hot-rolled silicon steel non-directional, so the three-phase iron core is the use of direct seams, laminated punching, iron column and iron yoke are With screw to defend the grip, the higher the core Zhu, seams in the core column. So the material of the magnetically permeable material and the structure of the iron core all determine that the no-load loss and the no-load noise have great values. Because the distribution transformers are installed on the poles of the platform, far away from the residential area, it is generally more use of oil-immersed distribution transformers, no performance assessment of the contents of no-load noise assessment.

Japan in 1964 invented the high permeability grain oriented cold-rolled silicon steel sheet, since 1968, the world has been able to buy this coil of silicon steel sheet, which promoted the structural improvement of the magnetic permeability system, the modernization of processing equipment, The distribution transformer to reduce the no-load loss, no-load noise reduction. Slitting line from the slitting production line will be 1000mm wide roll of material cut into a certain width of the coil, and then cut by the shear line into a certain shape laminates. Due to the directional cold-rolled silicon steel, the seam changed to 45 ° oblique seam. Since the coil can be cut into any length of lamination, there is no longer seam on the core leg. Due to the improvement of the lamination positioning method, there is no hole in the stem and the yoke, and the core post is tightly fastened by the glass adhesive tape, and the iron yoke is pulled by the pulling belt made of the adhesive tape, thereby greatly reducing the no-load loss The decline.

In the development of new distribution transformers, the role of magnetic materials is very important, but both of our country are relatively backward, there is no major breakthrough over the years, almost entirely by imports of silicon steel.

China's 64,73 standard transformers are mostly made of hot-rolled silicon steel core material, due to the non-directional hot-rolled silicon steel, so the three-phase core is the use of direct seams. Since the 1980s, China imported the coil of silicon steel sheet for the production of transformers. As the cold-rolled silicon steel sheet has the directionality, there is no longer any seams on the iron core column, the lamination positioning method is improved. The stem and the yoke Hole can be set within the film, during this period, most of the domestic production of transformers S7 series, a substantial reduction in load loss.

1990s, the world has also developed a thickness of only 0.23mm cold-rolled grain oriented silicon steel, silicon steel, such as laser or plasma by laser irradiation, then become the lowest unit loss of silicon steel products, 50Hz and 1.7 The unit loss under T (Tesla) is only 0.9W / kg. Iron core structure and the emergence of 45 ° joints of the latest ladder structure, so no-load loss and no-load noise and reduce again, so that distribution transformers to low loss, low noise development has taken another step forward, no-load loss reduced by 60% . Power distribution transformers also by the S7 series into the S9, S10 and other series.

In 1960 the United States California Polytechnic University found another amorphous alloy with good magnetic permeability, also known as metal glass. In 1974, United Credit Union developed an iron-based amorphous alloy. In 1978, the U.S. GE Company measured a unit loss of 0.44 W / kg at 60 Hz and 1.5 T (Tesla), a further 50% decrease from 0.9 W / kg. In 1980, Unicom first introduced 15kVA amorphous iron core distribution transformers, and later, the United States GE company made 2500kVA amorphous iron core distribution transformers. No-load loss was another 70% lower than laser-treated high-permeability grain-oriented cold-rolled silicon steel. China's Shanghai Forte Transformer Co., Ltd. to introduce the United States GE technology, in 1994 the introduction and development of the first batch of amorphous iron core distribution transformers, some plants have also had the ability to mass production of amorphous iron core distribution transformers.

It can be seen from the above review of the development history that the development of magnetically permeable materials promotes the modernization of magnetically permeable material processing equipment, the improvement of the iron core structure, the drastic drop of no-load loss and no-load noise, and the transformer can be installed near residential areas , Indicators meet the environmental requirements.