Amorphous alloy iron core transformer is a transformer made of a new type of magnetic material-amorphous alloy with an iron core. Compared with silicon steel sheet as an iron core transformer, the no-load loss is reduced by about 75%, and the no-load current is reduced by about 80%. It is a distribution transformer with ideal energy-saving effect at present, and is especially suitable for places with low load rates such as rural power grids and developing regions.

Amorphous alloy iron core transformer is a transformer made of a new type of magnetic material-amorphous alloy with an iron core. Compared with silicon steel sheet as an iron core transformer, its no-load loss is reduced by about 75%, and its no-load current is reduced by about 80%. It is a distribution transformer with ideal energy-saving effect at present, and is especially suitable for places with low load rates such as rural power grids and developing regions.

About amorphous alloy materials

At present, the Shanghai Iron and Steel Research Institute has been able to spray 140mm wide amorphous iron-based strip, its main features are:
(1) The thickness of the amorphous alloyed iron chip is extremely thin, only 20-30ftm, and the filling factor is relatively low, about 0.82.
(2) The permissible magnetic density of the amorphous alloy iron core is low, the single-phase transformer is generally 1.3 ~ 1.4T, and the three-phase transformer is generally 1.25 ~ 1.35T. Therefore, product design is highly restricted by materials.
(3) The hardness of amorphous alloy is 5 times that of silicon steel sheet, and it is very difficult to process and cut. Generally, transformer manufacturers can only use formed iron cores to manufacture amorphous alloy transformers.
(4) Amorphous alloy iron core materials are very sensitive to mechanical stress, whether it is tensile force or bending stress will affect its magnetic properties. Therefore, in the structure of the transformer body, it should be considered to minimize the force on the iron core.
(5) The magnetic domain expansion degree of amorphous alloy is about 10% higher than that of silicon steel sheet, and it is not suitable to be over-clamped. Therefore, the noise of amorphous alloy transformer is higher than that of silicon steel sheet iron core transformer.
The iron core of a three-phase amorphous alloy transformer consists of four frames combined into a structure similar to a three-phase five-column type with staggered iron choke joints. Both the iron core and the winding have rectangular cross-sections, but each has its own mechanical support structure.

Research on Amorphous Alloy Transformers Abroad

Since 1980, the United States Corporation of America first launched the 15kVA amorphous alloy iron core transformer, and has achieved remarkable results in the past 20 years.
Beijing Electric Power Company and Hitachi Electric Co., Ltd. have done in-depth and detailed research on the long-term reliability of amorphous alloy transformers. Since 1991, they have conducted accelerated aging, field operation, short circuit, and impact tests on 200 amorphous transformers of different capacities. They also conducted tests on the impact of load and vibration on the no-load characteristics of the transformer. The research results show that the amorphous alloy wound iron core distribution transformer, after accelerated aging test and on-site operation assessment of 200 amorphous transformers, has stable no-load characteristics and reliable operation during the 30-year life span.

Development of Amorphous Alloy Transformers in my country

The research and development of my country's amorphous alloy transformers began in the "Seventh Five-Year Plan". In the national scientific and technological research project "Amorphous Alloys and Alloys", "Development of Amorphous Alloy Core Distribution Transformers" is a key topic. In May 1986, Shanghai Iron and Steel Research Institute cooperated with Ningbo Transformer Factory to trial-produce the first single-phase 3kVA amorphous alloy transformer in China using the amorphous alloy strips developed by the institute.

In September 1988, Shanghai Iron and Steel Research Institute cooperated with Shanghai Metallurgical Equipment Factory and Shanghai Silicon Steel Sheet Factory to successfully develop a 100kVA three-phase amorphous distribution transformer with a traditional laminated structure. The no-load loss is 187W, which is equivalent to the same capacity S9-type silicon steel sheet transformer. 64% of no-load loss.

In August 1989, Shanghai Iron and Steel Research Institute and Luoyang Transformer Factory trial-produced a three-phase 30kVA wound amorphous iron core distribution transformer with no-load loss of 36.8w, which is about 72% lower than that of the S9 type with the same capacity.

From 1991 to 1995, the Shanghai Metallurgical Equipment General Plant used iron-based amorphous strip produced by the General Institute of Steel Research and trial-produced a number of 20kVA, 30kVA, 50kVA, 100kVA three-phase winding amorphous distribution transformers, which were provided by Hebei Zhuozhou Electric Power Bureau and Tianshui Agricultural Machinery Co., Ltd. carried out a network operation test. The overall level of no-load loss of amorphous distribution transformers is lower than that of S7-type silicon steel transformers with the same capacity. After the data and parameter analysis of the test in operation, it is proved that the energy-saving effect is remarkable, the operation is stable and reliable; it has the characteristics of low temperature rise and strong anti-overload ability.

In August 1995, in accordance with the decision of the Working Group of the Third Committee and the Third Ministry of "Promoting the Application of Amorphous Distribution Transformers in China", the Shenyang Transformer Research Institute was entrusted with a unified design based on the performance of the amorphous alloy strips of the United States Corporation, and organized Tianjin and Shanghai The six transformer factories of Beijing, North Second Substation, Foshan, Liaoyang and Baoding have trial-produced six prototypes of SHll—160, 200, 315, and 500kVA in four specifications, and passed the national appraisal.

In February 1998, Shanghai Zhixin Company introduced the amorphous transformer manufacturing technology and the amorphous transformer production line from GE of the United States and formally signed a contract. The SH-M type amorphous alloy sealed transformer produced has a rated capacity of 50kVA～2500kVA and a no-load loss of 34W. ~ 700W, the load loss is between 870W and 21500W, the no-load current is between 1.5%" and 0.5%, and the short-circuit impedance is between 4% and 4.5%.

Concluding remarks

To sum up, the overall development speed of my country's amorphous distribution transformers is relatively slow, and the main reason is the price. Amorphous alloy transformers are designed with low magnetic density, so the core volume and weight are too large, and the material price is higher than that of conventional silicon steel sheets. Although many places have explained a theory of "loss assessment", that is, the part of the more investment can be recovered from the saved electricity bills after a few years, but the effect of popularization and application is not satisfactory.
We firmly believe that, according to the current situation of resources in our country, with the joint efforts of all parties, the research and application of amorphous alloy transformers will surely have a faster and greater development in the new century.