Nanocrystalline materials have the advantages of silicon steel, permalloy, and ferrite at the same time. which is:
1. High magnetic permeability: The static initial magnetic permeability μ0 can be as high as 120,000 to 140,000, which is equivalent to permalloy. The magnetic permeability of the iron core used in power transformers is more than 10 times that of ferrite, which greatly reduces the excitation power and improves the efficiency of the transformer.
2. High magnetic induction: Saturation magnetic induction Bs=1.2T, which is twice that of permalloy and 2.5 times that of ferrite. The power density of the iron core is high, which can reach 15 kW to 20 kW/kg.
3. Low loss: In the frequency range of 20kHz～50kHz, it is 1/2～1/5 of ferrite, which reduces the temperature rise of the iron core.
4. High Curie temperature: The Curie temperature of nanocrystalline materials reaches 570°C, while that of ferrite is only 180°C-200°C.
Due to the above advantages, the transformer made of nanocrystals is applied to the inverter power supply, which has played a great role in improving the reliability of the power supply:
1. The loss is small, and the temperature rise of the transformer is low. The long-term actual use of a large number of users has proved that the temperature rise of the nanocrystalline transformer is far lower than that of the IGBT tube.
2. The magnetic permeability of the iron core is high, which reduces the excitation power, reduces the copper loss, and improves the efficiency of the transformer. The primary inductance of the transformer is large, which reduces the impact of the current on the IGBT tube when switching.
3. High magnetic induction and high power density, which can reach 15Kw/kg. The volume of the iron core is reduced. Especially for high-power inverter power supply, the reduced volume increases the space in the chassis, which is beneficial to the heat dissipation of IGBT tubes.
4. The overload capacity of the transformer is strong. Since the working magnetic induction is selected to be about 40% of the saturation magnetic induction, when overload occurs, only the magnetic induction generates heat, and the IGBT tube will not be damaged due to the saturation of the iron core.
5. The Curie temperature of the nanocrystalline material is high. Assuming that the temperature reaches above 100°C, the ferrite transformer can no longer work, but the nanocrystalline transformer can work normally.
These advantages of nanocrystalline have been recognized and adopted by more and more power supply manufacturers. A number of domestic manufacturers have adopted nanocrystalline iron cores and have used them for many years. More and more manufacturers are beginning to use or trial. At present, it has been widely used in inverter welding machine, communication power supply, electroplating electrolysis power supply, induction heating power supply, charging power supply and other fields, and there will be a greater increase in the next few years.