Magnetic components are usually composed of windings and magnetic cores. It is a necessary power electronic device for energy storage, energy conversion and electrical isolation. It mainly includes transformers and inductors. In almost all power circuits, magnetic components are inseparable. Magnetic components are one of the most important components of power electronic technology. Classification of magnetic components Magnetic components are mainly divided into transformers and inductors. The main function of the transformer is isolation, voltage conversion, etc., and its core is energy transfer. The main function of inductance is resonance, filtering, etc., and its core is energy storage. Although magnetic components such as electronic transformers and inductors are just small seemingly inconspicuous parts, they play an indispensable role in products such as new energy vehicles, LED power supplies, and photovoltaic inverters. Generally speaking, electronic transformers play the role of voltage transformation, filtering, and energy storage in products, while inductance is to solve EMI problems, electromagnetic compatibility, and so on. Measurement of magnetic components The most common and widely used soft ferrites currently produced are manganese-zinc ferrite (for low frequency) and nickel-zinc ferrite (for high frequency). When the factory leaves the factory, one end of the medium-wave magnetic rod of the manganese-zinc tongue retractor is often painted with black paint, and one end of the nickel-zinc short-wave magnetic rod is painted with red paint. These three methods can be used: 1. Visual inspection method 2. Water milling method 3. Measure with a multimeter. Application of magnetic components The figure below is a typical switching power supply structure, the yellow part is the application of magnetic devices. In addition, the auxiliary power supply also needs a flyback transformer, and there is a PFC inductor in the PFC circuit. Sometimes the output port of the power supply will increase the EMC filter inductor based on EMC requirements. The importance of magnetic components Generally speaking, the volume of the magnetic device accounts for about 20% to 30% of the entire switching power supply, the weight accounts for about 30% to 40%, and the loss accounts for about 20% to 30%. From the figure below, you can intuitively feel the position of magnetic devices in the switching power supply. Magnetic component technology is very important for power converters. In almost all power circuits, magnetic components, inductors or transformers are inseparable. For example, inductance is used at the input and output to filter out the harmonics of the switching waveform; in the resonant converter, the inductor and capacitor are used to generate resonance to obtain sine wave voltage and current; in the snubber circuit, the inductance is used to limit the current change rate of the power device ; In the boost converter, energy storage and transmission; sometimes inductance is used to limit the transient current of the circuit. The transformer is used to electrically isolate the two systems, transform voltage or impedance, or produce phase shift (3-phase delta-Y transformation), store and transfer energy (flyback transformer), and voltage and current detection (voltage and current Transformer). It can be said that magnetic components are one of the most important components of power electronics technology.

1. Definition and development characteristics of high-performance NdFeB permanent magnet material industry The high-performance NdFeB permanent magnet material is made by the rapid-setting stripping method, and the sum of the intrinsic coercive force Hcj (KOe) and the maximum magnetic energy product (BH) max (MGOe) is greater than 60. The sintered NdFeB permanent magnet material (definition From the "China High-tech Product Catalog 2006"). The performance of high-performance NdFeB permanent magnet materials is mainly characterized by parameters such as coercivity, remanence, maximum energy product, and maximum operating temperature. The definition of each parameter and the unit of measurement are as follows: The development of my country's high-performance NdFeB permanent magnet material industry started relatively late. As a pioneer in the domestic high-performance NdFeB permanent magnet material industry, Yantai Zhenghai Magnetic Materials introduced the then world-class complete set of production equipment from abroad in 2001. Two years of equipment debugging and technical transformation, combined with the oxygen-free production process with independent intellectual property rights, produced my country’s first batch of intrinsic coercivity Hcj (KOe) made by the rapid-setting stripping method in 2003 High performance neodymium iron boron permanent magnet material with the sum of the maximum magnetic energy product (BH) max (MGOe) greater than 60. After 2004, other NdFeB permanent magnet material manufacturers in my country, such as Ningbo Yunsheng, Zhongke Sanhuan, etc., have gradually introduced equipment from abroad to produce high-performance NdFeB permanent magnet materials, making my country's high-performance NdFeB permanent magnets Material output is growing rapidly. In 2006, in order to better support the development of the high-performance NdFeB permanent magnet material industry, my country included high-performance NdFeB permanent magnet materials in the "China High-tech Product Catalog 2006". At present, due to factors such as the distribution of rare earth resources and cost considerations, European and American countries have transferred the production bases of NdFeB permanent magnet materials to my country. Only Germany and Finland still maintain a certain output, and only produce high-performance NdFeB permanent magnet materials. Due to the limitation of the patents of the basic composition of NdFeB, my country's high-performance NdFeB permanent magnet materials cannot enter the international market on a large scale for the time being. The permanent magnet material industry will usher in a period of rapid development.

The first quarter is over. Magnetic component manufacturers have been plagued by the price increase of raw materials in the first quarter of this year, dispersing their efforts in market development. The high raw material prices have caused magnetic component manufacturers and their downstream manufacturers to make prices. Game. At the beginning of the Year of the Ox, the price of industrial metals led the raw material market. The entire industrial manufacturing industry was anxious and panicked. It was difficult for anyone to be alone. Each link in the industrial chain was conducted one by one. Internal emergency meetings and business negotiations were all for the purpose of Industry linkage, jointly bear the difficulty of price increase. 　　 When the price of raw materials is rising! 　　 After the festival, with the steadily rising global oil prices, various chemical raw materials have jumped. According to the research media, domestic bulk commodities have continued to rise since June last year. As of the end of February, integrated circuits have soared by more than 100%, paper prices by 50%, zinc alloys by 48%, stainless steel by 45%, copper prices by 38%, aluminum prices by 37%, plastics by 35%, and iron prices by 30% , Glass rose 30%. 　　 　　According to incomplete statistics on global plastics, the current price increase in the domestic chemical industry has become an overwhelming trend. The price of some products has increased by more than 10,000 yuan/ton year-on-year, and the price increase has reached more than 153%. DuPont, SK, Nanya Plastics, BASF, Songyuan Group, Changchun Chemical and other engineering plastics companies issued price adjustment announcements at the end of February, with varying price increases. 　　 Dongguan Nanjida Industrial Co., Ltd. specializes in the production of high/low frequency transformer cores (also known as "framework" in the industry), power supply housings, LED lamp housings and other products. These products are injection molded products, and the basic raw material is plastic. Li Xiang, deputy general manager of the company's marketing department, told reporters that the purchase price of raw materials for their products such as skeletons has increased by 20% in recent times. 　　 　　 Magnetic cores are the supply chain of magnetic component manufacturers, and the raw material purchase prices of magnetic core manufacturers have also increased to varying degrees. Encore Magnetic Devices Co., Ltd. independently develops, produces and sells sendust, sendust, super sendust, and iron-nickel products. General Manager Wang Liping said that the total purchase price of these products has increased by 30% recently. 　　Compared with the above-mentioned raw materials, rising copper prices have hit the electronics manufacturing industry the most deadly. The data shows that since the copper price rose from a low of US$4,371/ton in March 2020 to a high of US$9,617/ton in February this year, copper prices have risen by more than 100%. Spot copper prices in February hit a new high in the past ten years. 　　 Copper futures are also rising all the way. As of 15:00 on April 2, the main Shanghai copper futures contract was reported at 67,090 yuan/ton, which is down from the previous high of 70,800 yuan/ton, but the overall trend is still high. Even if it is scrap copper, the price has risen. Just after the Spring Festival, many scrap copper purchase station owners made overnight profits. The "worth" of scrap copper that was forced to hoard due to epidemic prevention and control a year ago has skyrocketed, and even "a piece of copper is hard to find" situation.  In the domestic market, due to the full recovery of China's economic production, commerce and tourism have also been fully opened up, which has promoted the improvement of the economy and stimulated the demand for copper and other industrial metals. Starting from the third quarter, the growth rate of investment in power grids and power sources will continue to increase in order to achieve the goal of the full-year investment plan. In foreign markets, the rate of new crown pneumonia vaccination in developed countries has gradually increased, and investment in the global communications field has increased the demand for copper materials in 2021. Major mining countries are still facing the impact of the epidemic, and the operating rate of mining facilities has always been difficult to return to normal. The gap could not be filled. As a result, economists have analyzed that the LME copper price for the entire year of 2021 can at least increase by more than 10%. The price increase has been transmitted to the consumer terminal In this surge of raw material prices, the electronics manufacturing industry bears the brunt of the impact of rising raw materials. Whether it is upstream electronic transformers or downstream consumer electronics, home appliances, industrial equipment and other terminal products, metal materials are the