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Electronic transformer use
The application of electronic transformer in the traditional lighting lamps in the very popular, such as fluorescent lamp, lamp, energy-saving lamp, advertisement lamp and so on almost all can use the electronic transformer, and the electronic transformer, can save the starter. In the LED lighting, new products are mostly used in electronic transformers. Transformer is mainly in the transformer function, high efficiency, cost savings, iron and copper materials, small structure, light weight. The problem is that the resistance of the voltage and the high current is worse than that of the iron transformer.
Application in power supply technology
The electronic transformer in the power supply device usually uses an electronic transformer made of soft magnetic core. Although there have been no soft magnetic core of the hollow core transformer and piezoelectric ceramic transformer, however, by the early twenty-first Century, the vast majority of the power supply device in the electronic transformer, still use soft magnetic core.
Therefore, to discuss the relationship between power technology and electronic transformer, electronic transformer in power supply technology, the role of power supply technology of electronic transformer, electronic transformer adopts new soft magnetic materials and new core structure of power technology development impact, will cause the power industry and the soft magnetic material industry friends interest. Some of the views put forward in order to promote Baidu encyclopedia, between the power industry and electronic transformer industry and soft magnetic materials industry on the issue of electronic transformer and soft magnetic materials for dialogue, mutual exchanges and common development.
1, power supply technology requirements for electronic transformers
Power technology requirements for electronic transformers, like all products as a commodity, is the use of specific conditions to complete the specific function of the pursuit of the best performance price ratio. Price and cost may sometimes be biased, and sometimes may be biased towards efficiency and performance. Light, thin, short, small is the development direction of electronic transformers, is to emphasize the cost reduction. From the general requirements of the electronic transformer can get four specific requirements: the use of conditions, complete functions, improve efficiency and reduce costs. [4]
2, the use of the conditions of the use of electronic transformers, including two aspects:
Reliability and electromagnetic compatibility. Reliability refers to the specific conditions of use, the electronic transformer can work until the service life. Ambient temperature is the most important influence on electronic transformer in general use conditions. The parameter that determines the strength of the transformer affected by temperature is the Curie point of the soft magnetic material. The soft magnetic material has a high Curie point and is affected by the temperature. The soft magnetic material has a low Curie point and is sensitive to the temperature change.
For example: a comparison of Mn Zn ferrite Curie only 215 degrees, low loss, permeability and magnetic flux density, with temperature changes, in addition to the normal temperature 25 degrees outside, but also give 60 degrees, 80 degrees, 100 degrees of various parameters. Therefore, the working temperature of the Mn Zn ferrite core is generally limited to 100 DEG C, that is, when the ambient temperature is about 40 DEG C, the temperature rise must be less than 60 DEG C. The Curie point of the Co based amorphous alloy is 205 DEG C, and the temperature is limited to below 100 DEG C. The Curie point of the Fe based amorphous alloy is 370 DEG C, and can be used at a temperature of less than 150 DEG C to about 180 DEG C. The Curie point of the high magnetic conductivity permalloy is 460 DEG C to 480 DEG C, and can be used at a temperature of 200 DEG C to less than 250 DEG C. The Curie point of the microcrystalline nanocrystalline alloy is 600 DEG C, and the point of view of the oriented silicon steel is at the temperature of 730 DEG C, which can be used at the temperature of 300 DEG C to 400 DEG C. Electromagnetic compatibility refers to the electronic transformer does not produce electromagnetic interference to the outside world, but also to withstand external electromagnetic interference. Electromagnetic interference includes audible audible noise and audible high-frequency noise. The main reason of electromagnetic interference of electronic transformer is the magnetostriction of magnetic core. Large magnetostrictive coefficient of soft magnetic materials, resulting in large electromagnetic interference The magnetostriction coefficient of Fe based amorphous alloys is usually the largest (27 ~ 30) * 10-6, which must be taken to reduce the noise interference. The magnetostriction coefficient of high magnetic conductivity Ni50 permalloy is 25 * 10-6, and the magnetostriction coefficient of Mn Zn ferrite is about 21 * 10-6. These 3 kinds of soft magnetic materials are materials which are easy to produce electromagnetic interference. The magnetostriction coefficient of the 3% oriented silicon steel is from (1 ~ 3) * 10-6, the magnetostriction coefficient of the nanocrystalline alloy is (0.5 ~ 2) * 10-6. These 2 kinds of soft magnetic materials are relatively easy to produce electromagnetic interference materials. 6.5% the magnetostriction coefficient of the silicon steel is about 0.1 * 10-6, the magnetostriction coefficient of the high magnetic conductivity Ni80 permalloy is (0.1 ~ 0.5) * 10-6, the magnetostriction coefficient of the Co based amorphous alloy is less than 0.1 * 10-6. These 3 kinds of soft magnetic materials are materials that are not easy to produce electromagnetic interference. The frequency of electromagnetic interference generated by magnetostriction is the same as that of the electronic transformer. If there is an electromagnetic interference below or above the operating frequency, that is caused by other reasons.
3, the completion of the function of electronic transformer from the main transformer and transformer to distinguish between 2.
Special components to complete the function of another discussion.
Transformer has 3 functions: power transmission, voltage conversion, insulation isolation;
The inductor has 2 functions: power transfer and ripple rejection. There are 2 ways of power transmission.
The first is the transformer transmission, namely external alternating voltage in the primary winding of the transformer, the flux changes in the core, the induction voltage of secondary winding, and the load, so that the electric power transmitted from the primary side to the secondary side. The transmission power is determined by the induced voltage, which is determined by the flux density variable B. The B is independent of the permeability, but is related to the saturation flux density Bs and the residual magnetic flux density Br.
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