Amorphous alloy core transformer

With the development of my country's electric power industry and the continuous deepening of the construction and transformation of urban and rural power grids, amorphous alloy core transformers, with their obvious advantages of low no-load loss, energy saving and environmental protection, are in line with the "saving resources and protecting the environment" advocated by the Chinese government. The industrial policy of "building a conservation-oriented society" is increasingly favored by the majority of power users. In order to speed up the upgrading of transformer products, improve energy saving levels and reduce line losses, transformer manufacturers across the country have increased their production and research and development of amorphous alloy core transformers.

Amorphous alloy material
Amorphous alloy material is a new type of energy-saving material. It is mainly made of iron, nickel, cobalt, chromium, manganese and other metals as alloy base, and adds a small amount of boron, carbon, silicon, phosphorus and other metal elements. It has Good ferromagnetic properties.

The amorphous alloy material adopts a rapid rapid solidification production process. Its physical state is characterized by a disordered amorphous arrangement of metal atoms. It is completely different from the crystal structure of silicon steel and is more conducive to magnetization and demagnetization. The processed amorphous alloy core The thickness of the strip is only 0.025mm. This new material can be used to magnetize the transformer core very easily. It can significantly reduce the no-load loss of the transformer. However, its magnetic flux saturation value is lower than that of traditional silicon steel materials (1.57T-1.59T). Therefore, when designing the magnetic flux density of the amorphous alloy core, the single-phase transformer generally takes 1.3T-1.4T, and the three-phase transformer generally takes 1.25T-1.35 The value between T is ideal.

The amorphous alloy core material is very sensitive to mechanical stress. Both tensile force and bending stress will affect its magnetic properties. Therefore, the loss of the core will increase as the stress increases. This needs to be fully considered in the structural design of the machine body. Structure and characteristics of amorphous alloy core transformer
1. Iron core structure

The amorphous alloy strip used in the amorphous alloy iron core has a complicated processing technology. The material is hard and brittle, difficult to shear, and difficult to deform. Therefore, the current strip specifications only have three widths: 142mm, 170mm, and 213mm. The amorphous gold iron core can only be made according to the The transformer capacity needs to be made of strips of corresponding widths into long rectangular sections. From a structural point of view, the lower iron yoke is generally designed as an open single-roll core structure with staggered overlapping seams to facilitate combination into single-phase or Three-phase transformer core. At present, domestic three-phase amorphous alloy core transformer core structures mainly include three-phase five-column (Figure 1) and three-phase flat wound core (Figure 2). Among them, the three-phase five-column type is more common. Usually, small distribution transformers of 10KV level and capacity below 500KVA adopt a four-frame five-column structure with four rolled iron cores. When the capacity is large, due to the limitation of the width of the amorphous alloy strip, generally Eight rolled cores are stacked together in front and rear rows to form a core structure with a larger cross-sectional area. Using this stacked structure, the capacity of a single amorphous alloy core transformer can reach 2500KVA.

In the design of amorphous transformers, the lamination coefficient of the amorphous strip core is generally in the range of 0.82-0.86, while the no-load loss process coefficient is generally about 1.4, which is more appropriate. The thickness coefficient of the core opening superposition is roughly 1.25 in China. and 1.18. The specific selection of its value should be determined with the selected amorphous alloy core manufacturer before production.