Nanocrystalline materials used in the merits and problems of the power inverter
High frequency inverter power supply operating frequency from 20kHz to 50 kHz, as the main transformer of the power the heart, the traditional core materials, ferrite is low loss at high frequency is not very good, but the magnetic properties of low frequency (100kHz) lower, the size and weight of the core, but also because of the saturation magnetic induction value (Bs) is still large, in addition, the lower the Curie temperature of the ferrite, poor thermal stability, higher temperature, lead to lower Bs value, easy to saturation unstable working state, not suitable for use in high frequency high power. Nanocrystalline materials with excellent magnetic properties, especially used in high-frequency high-power inverter power inverter transformer core has come out on top.
Advantages of nanocrystals
Nanocrystalline materials at the same time with the silicon steel, permalloy, ferrite advantages. Namely:
High magnetic induction: double the saturation magnetic induction Bs = 1.2T, is permalloy alloy, ferrite, 2.5 times. The core power density can reach 15 kW ~ 20kW/kg.
High permeability: the static initial permeability μ0 can be as high as 120,000 to 140,000, with permalloy. For the power transformer core permeability ferrite 10 times, greatly reduce the excitation power, improve the efficiency of the transformer.
Low-loss ferrite 1/2 ~ 1/5: 20kHz ~ 50kHz frequency range, reducing the core temperature rise.
Curie temperature: the nanocrystalline materials, the Curie temperature of 570 ° C, the ferrite Curie temperature is only 180 ℃ to 200 ℃.
Due to the above advantages, the application of nanocrystalline manufacturing transformers on the power inverter, power supply reliability to improve play a significant role:
Loss of small, low temperature rise transformers, large number of users of long-term real use to prove the nanocrystalline transformer temperature rise is much lower than the temperature rise of the IGBT tube.
High core permeability, reducing the excitation power, reduces the copper loss, improve the efficiency of the transformer. The primary inductance of the transformer, reducing the impact of the current at turn-off IGBT tube.
Work high magnetic flux density, power density, can reach 15Kw/kg. Reduce the volume of the core. In particular, power inverter power supply, the volume is reduced such that the increased space in the chassis, IGBT cooling of the tube.
Transformer overload, work magnetic sense to select about 40% of the saturation magnetic induction, when an overload occurs, only because of the increased magnetic induction of fever, without core saturation and damage to the IGBT tube.
High Curie temperature of nanocrystalline materials, assume that the temperature reaches 100 ℃, the ferrite transformer does not work, the nanocrystalline transformer can work properly.
Nanocrystals these advantages, a growing number of power supply manufacturers to understand and use, the domestic number of production plants has been adopted nanocrystalline core, and for many years. More and more manufacturers begin to use or try. Has been widely used in the field of inverter welding machine, communication power supply, electrolytic plating power induction heating power supply, rechargeable power in the coming years there will be a more substantial increase.
Second, people are concerned about several issues
Nanocrystalline materials applied to the inverter power supply, there were some problems such as noise, brittleness, consistency issues, and promote the use of impact to a certain extent, caused concern. Now these problems have been solved step by step.
(A) noise problems
The noise in the formation of a variety of reasons:
A. The reason of the magnetostriction coefficient of the material itself, the magnetostriction coefficient of ferrite material is relatively large, although the ferrite core is solid, sometimes in the use of noise. Nanocrystals different compositions, different magnetostriction coefficient, a few years ago to use components, a generic composition of the alloy, to create the transformer noise problems with the application, the development of more and more in-depth for different use a different alloy composition, to meet the special requirements of different devices on the magnetic properties. For example, as the power output transformers, current transformers, common mode inductance, etc., have developed special ingredients. According to the requirements of the power transformer to adjust the alloy composition, reducing the magnetostriction coefficient by the user to prove the noise problem has been greatly improved.
Two. Winding core elastic on the reasons, with the use of strip quality with the deviation of the timber size, uneven thickness will cause the core winding tight, noise-prone. After adjustment of the composition, the molten steel fluidity, with the forming quality of the material, to a certain extent in order to reduce the core noise, providing a favorable guarantee.
3. Aspects of the inverter circuit, the DC component in the circuit, the core of the magnetic induction increase, caused by noise. Our experiments show that noise increases with the increase of the working magnetic induction. Some manufacturers in the DC blocking measures taken on the circuit, nanocrystalline core over the years does not appear to noise problems.
The above improvements, the basic noise problem has been resolved.
(B) brittle
The dregs of the brittleness of the main reaction of the nanocrystalline core in the core, users complained that the biggest problem, not only for the installation of the operating headaches, and easy to cause a short circuit hidden danger to the circuit. After years of practice, research, brittleness of the adjustment of the composition, process, greatly improved. Composition adjusted, the flexibility of the strip significantly improved. The thinning of the strip thickness to reduce brittleness. In addition, in the process of manufacturing iron core on the core impregnation stress-free glue, making the core easily broken, completely solved the core of the dregs of the brittleness problem. At the same time, due to stress-free plastic core with a material layer gap is fixed, it is not easy to produce resonance, reducing the noise generated.
(C) consistency problem
Consistency with the scale of production is related with the capacity of the production equipment. See from the quality of the strip, a 500 kg production equipment and 50 kg of production equipment, the same production of 500 kg strip, obviously, the former product composition, magnetic properties of consistency is better than the latter. The same heat treatment in the production process is the same. Large-scale production, large capacity of production equipment on the consistency of benefit.
The nanocrystals consistency in the user, mainly in the saturation voltage and the inductance of discrete, sometimes a difference of more than doubled. The main reason is the effect of magnetic field heat treatment production testing are not classified screening. With the adjustment of the composition for the power transformer, not only to improve the brittleness, but also reduces the residual magnetic flux density of the material, therefore, increases the effect of heat treatment of the magnetic field, the saturation voltage of the core, played an important role on product consistency .
Inverter power supply required by the magnetic energy, there is a gradual process of understanding a few years ago, due to the smaller amount, stressing only the loss to meet the requirements can Therefore, the performance test to measure only the loss of a parameter. Specific user, increasing the test value of the induced voltage. With the increasing amount of applications, a variety of demands followed by raised, in particular the requirements of the consistency of performance is particularly prominent. An understanding of the process to such a request, regardless of improvements in the composition, organization of production, testing standards, have some lag. Promote the use of certain influence. This issue is now sufficient knowledge and has taken various effective measures, consistency has been greatly improved.
(D) the price
The price problem is that users are most concerned about, in particular, the user is ready to use or just beginning to use. Price and production in recent years, with the nanocrystalline core applications are becoming increasingly widespread, not only for inverter welding machine, and is used extensively for the electrolytic plating equipment, induction heating equipment, charging equipment, communications power supply, UPS power supply, X-ray power, laser power, frequency control, power and other fields, increasing production, prices have reduced significantly, the current price is higher than the initial price has fallen by about 40%, with applications increasing, prices will be getting lower and lower, the nanocrystals prices will become increasingly close to the price of ferrite.
For more than 15 kilowatts of high-power power, in fact, the price of the nanocrystalline core has been lower than the ferrite core. Because of the limited size of the ferrite core, high-power transformer core is difficult to solve, and had to use several core in order to meet the power requirements. Nanocrystalline core one. Point of view from the unit price, ferrite are much cheaper, but the total price of a few core NONSTOICHIOMETRIC NANO crystalline core price.
Third, the nanocrystalline transformer products
Nanocrystalline transformer used in almost all of the whole production plants around the system, the factory inverter circuit design, understanding of the nanocrystalline materials, manufacturing process mastery of the transformer, to create a transformer level different. Manufacture of high-frequency transformer to become an important part of the production. Therefore, the number of manufacturers, the specialized production of high-frequency transformer, the whole plant buy the transformer.
Original 20kHz to 50kHz frequency range of the transformer, generally used ferrite transformer core, the core form of the U-shaped or EI, a minority use O-core, U-shaped or EI core structure is difficult to reduce transformer leakage inductance.
The advantages of nanocrystalline materials, provides the ideal materials for miniaturization of high frequency transformer, efficient. New materials to promote the high-frequency transformer to the birth of a new structure.
This patented the name "Beetle" transformer, others improved after referred to as "H" type transformer, also received the patent, the two transformers take full advantage of the high permeability of the nanocrystalline materials, high magnetic flux density, loss low magnetic properties and the annular core leakage magnetic characteristics, at the beginning of the transformer, the secondary structure of the innovation. The core of the protective metal box as the secondary winding of the transformer, suitable for high current output, the primary coil around on the secondary leakage inductance is very small. Transformer fixed support and the convergence of output combined into one, allows for heat dissipation.
The advantage of this transformer is:
A. Power: 10 kW to 20kW, the power density can reach 15 kW ~ 20kW/kg
Two. Leakage inductance is small, the general level of less than 5μH best less than 2μH
3. High efficiency, more than 99%
4. Small size, light weight, 15 kW transformer weighs 3 kg, a volume of 160 × 150 × 95 mm
5 And aesthetic appearance.
Due to the structure and processing and other aspects of this transformer, the price is relatively high, only a certain number of applications for electroplating, electrolysis power supply. There are difficulties for a price competitive industry promotion. To this end, it launched a "Ω"-type transformers.
"Ω"-type transformer structure and toroidal transformer is the same, but the winding method is improved, thereby reducing the leakage inductance and distributed capacitance. The leakage inductance can generally be less than 10μH. The price of this transformer is about 40% lower than the "Beetle" or "H" type transformer. Excellent performance and low cost to attract a lot of manufacturers.
Nanocrystalline transformer products, reasonable use of the performance of nanocrystalline materials; conducive to high-frequency power transformer products, standardization; conducive to the transformer efficiency, raising the level of; conducive inverter welding machine, electroplating, electrolysis and other equipment
Production efficiency. There are several manufacturers able to produce such a transformer.
There are already some machine manufacturers began to use the "Ω"-type transformers, integrated production, which is a "more, faster, better, the provincial" initiatives.
IV Conclusion
Amorphous and nanocrystalline soft magnetic materials because of its outstanding characteristics in different applications to make up for the lack of silicon steel and ferrite materials, various types of electronic products to a new level, to improve efficiency, achieved remarkable energy saving effect. The new material shows a vibrant vitality.
Now, more and more people recognize the amorphous, nanocrystalline materials, in addition to the transformer outside of amorphous, nanocrystalline materials can also be as a transformer, the core material of the reactors, sensors, filters and other devices, the application scope of related to our daily lives in the household appliances, smart meters, DC inverter air conditioner, leakage protection switches, etc., measurement of the power system of power transmission, power distribution, telemetry sensors, the railway system of the locomotive air conditioning, electric locomotive inverter power, railway signal sensing applications in aerospace, aviation, marine and many other military and national high-tech projects to be typecast using.
You are here: News
BOM component procurement 