Introduction to the characteristics of nanocrystalline materials
Introduction to the characteristics of nanocrystalline materials Nanocrystalline materials also have the advantages of silicon steel, permalloy and ferrite. which is: 1. High magnetic permeability: The static initial permeability μ0 can be as high as 120,000 to 140,000, which is equivalent to permalloy. The magnetic permeability of the iron core of the power transformer is more than 10 times that of the ferrite, which greatly reduces the excitation power and improves the efficiency of the transformer. 2. High magnetic induction: the 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 large, which can reach 15 kW to 20 kW/kg.
3. Low loss: in the frequency range of 20kHz to 50kHz, it is 1/2 to 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℃, and the Curie temperature of ferrite is only 180℃～200℃.
Due to the above advantages, the transformer made of nanocrystals is used in the inverter power supply, which has played a great role in improving the reliability of the power supply:
1. The loss is small, the temperature rise of the transformer is low, and 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 high permeability of the iron core 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 during switching.
3. The working magnetic induction is high and the power density is high, which can reach 15Kw/kg. The volume of the iron core is reduced. Especially the high-power inverter power supply, the volume reduction increases the space in the chassis, which is beneficial to the heat dissipation of the IGBT tube.
4. The overload capacity of the transformer is strong. Since the working magnetic inductance is selected to be about 40% of the saturation magnetic inductance, when the overload occurs, only the magnetic induction produces SF heat, and the IGBT tube will not be damaged due to the saturation of the iron core. 5. The Curie temperature of nanocrystalline materials is high. If the temperature reaches above 100 °C, the ferrite transformer can no longer work, and 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 applied them for many years. More and more manufacturers are starting to use it. At present, it has been widely used in inverter welding machine, communication power supply, electroplating and electrolytic power supply, induction heating power supply, charging power supply and other fields, and there will be a greater increase in the next few years.