In the process of application of nanocrystalline cores, there have been noise problems, which have affected the popularization and caused concern in application. And now this problem have been gradually solved.
There are many reasons for the formation of noise:
1) The reason for the magnetostrictive coefficient of the material itself, and the magnetostrictive coefficient of the ferrite material is relatively large, although the ferrite core is solid, but sometimes noise occurs in use. The composition of nanocrystalline alloy ribbon is different, the magnetostriction coefficient is different, and the composition used in the past few years is the composition of a common alloy, so the noise problem of the transformer is more prominent. With the application and development of more and more in-depth, different alloy components are used for different purposes to meet the special requirements. For example, as a high frequency power transformer, current transformer, common mode choke etc., special components have been developed. The alloy composition adjusted according to the requirements of the power transformer has reduced the magnetostriction coefficient, and the noise problem has been greatly improved in use.
2) The reason for the tightness of the nanocrystalline cores in winding, which has a great relationship with the quality of the nanocrystalline strip, the size deviation of the strip, the uneven thickness will cause theiron core winding is not tight, and which will be easy to produce the noise. After adjusting the composition, the flow of molten steel is good, which is conducive to the forming quality of the nanocrystalline tape, and provides a favorable guarantee for reducing the noise of the nanocrystalline core to a certain extent.
3) Problems in the inverter circuit, the DC component in the circuit is large, which increase the magnetic induction of the iron core and cause noise. Our experiments shows that the noise increases with the increase of magnetic induction. Some manufacturers have taken measures to isolate DC on the circuit, and there has been no noise problem with nanocrystalline iron cores for many years.
The noise problem of nanocrystalline cores has been basically solved through the above improvement.
