The power transformer is the power transmission function, voltage and insulation, as a kind of soft magnetic components, widely used in power technology and power electronic technology. According to the transmission power, the power transformer can be divided into several files: 10kVA above for high power, 10kVA~0.5kVA power, 0.5kVA~25VA small power 25VA, the following is a micro power. Different transmission power, power transformer design is not the same, should be self-evident. Some people according to its main function is to transmit power, the English name "Power Transformers" translated into "power transformer" in many literatures are still in use. It is called "the power transformer", or "power transformer" good? The authority to be technical terms to the choice.
The same English name "Power Transformer" can also be translated into "power transformer". Power transformer is mainly used for power transmission and distribution system in power transmission, voltage and insulation effect, the primary voltage for high voltage 6kV or 5kVA power, minimum, maximum 10000 kVA. power transformer and power transformer, though the working principle is based on electromagnetic induction principle, but emphasizes power transmission of large power transformer, and emphasizes the insulation of high voltage isolation, both in the core coil, or insulation structure design, and the power transfer of small, low voltage power transformer insulation isolation have significant differences, but not the optimal design condition of power transformer design mechanically applied to power transformer. Design method of power transformer and a power transformer is not the same, should be self-evident.
High frequency power transformer is more than the working frequency of intermediate frequency (10kHz) power transformer, mainly used for high frequency switching power transformer in high-frequency switching power supply, but also for the high frequency inverter transformer high frequency inverter and high frequency inverter. According to the level of work frequency, can be divided into several grades: 50kHz~100kHz, 100kHz~500kHz, 10kHz~50kHz, 500kHz~1MHz 1MHz. Transmission power is relatively large, relatively low working frequency; transmit power is relatively small, the working frequency is relatively high. Thus, both the frequency difference and transmission power difference, design method of power transformer working frequency of different grades are not the same, should be self-evident.
As mentioned above, the author of the high frequency power transformer design principles, requirements and procedures are not wrong concept, but in the beginning of July 2003, a special reading "application" power technology in 2003 sixth recommended 2 high frequency magnetic components design of the article, had doubts, feel some problems worthy of further discussion, so to write this article. As the "power technology application" message editor said: "concrete analysis of concrete conditions," write the purpose, try to figure out the design problem of high frequency power transformer is one of the most difficult details and the choice of the magnetic element. If the wrong place, please several authors and the majority of the reader.
2 design principles of high frequency power supply transformer
High frequency power transformer as a natural product, with the attributes of goods, so the design principle of high frequency power transformer and other commodities, is to complete the specific function in the pursuit of the best price performance in the use of specific conditions. May lay particular stress on performance and efficiency, may lay particular stress on the price and cost. Now, light and thin and short small, become the development direction of the high frequency power supply, is the emphasis on cost reduction. The high frequency power transformer becomes a major difficulty, need more efforts in this regard. So in the high frequency power transformer "design" in the text, only talk about performance, no cost, can not be said to be a big disappointment, if you can consider the design principle of high frequency power transformer, the pursuit of better performance price ratio, transfer to single chip switching power supply high frequency transformer 10VA, we should design more light, thin, short and small Don't talk about the plan. The cost value of the rule of market is merciless! Many of the good performance of the products, often because of the price for the market can not accept being snubbed and eliminated. Often a new product cost was finally rejected. Some "section is not saving money" products in the market promotion on why it is worth pondering.
The cost of products, including not only the material cost, production cost, including development cost, design cost. Therefore, in order to save time, based on past experience, the high frequency power transformer iron loss and copper loss ratio, leakage and magnetizing inductance, the proportion of primary and secondary winding loss ratio, current density and provides some reference data, the degree of the filling of the window, and recommend some winding structure scheme, have what not good? Why must calculate and simulation went through channels to and fro, not only the concept of error? The author has developed the high-frequency amplifier switching power supply in 1980s, to the lowest temperature conditions, conducted optimization design of high frequency power transformer due. It is difficult to determine the thermal resistance, the sample results and far, have to fix it again. Now some of the company's core product specification, in order to shorten the design of high frequency electricity users The source of transformer, some simplified design formulas are listed, some with lists in a transmit power core frequency. This is for the sake of users, and promote win-win behavior of the company's products, is completely consistent with the law of the market, is not what needs the wrong concept analysis. The problem is to provide the reference data and whether the recommended scheme is experience? There is no universal? "Some claims of" the need after the test of practice, to stand.
In short, do remember: the high frequency power transformer is a product (i.e. commodity), the design principle is in the