Summary:

　　With the release of the GAC Aian Quark amorphous motor , the concept of amorphous materials suddenly became popular. I found an article to popularize the relevant basic knowledge for everyone.

　　This paper describes the characteristics of amorphous materials and the excellent performance and advantages of amorphous motors. Through the application examples of amorphous material disc permanent magnet motors, the application of amorphous materials in the field of high-efficiency motors is introduced.

　　1 Introduction

　　At present, my country's industrial energy consumption accounts for about 70% of the total energy consumption, of which the motor energy consumption accounts for about 60% to 70% of the industrial energy consumption. According to the survey, the market share of IEI motors in my country is close to 90%, while the proportion of high-efficiency and energy-saving motors above IE2 is only 8%. At present, the installed capacity of electric motors in my country is about 1.2 billion kilowatts. It is estimated that by 2020, the installed capacity of electric motors in my country will reach about 4.5 billion kilowatts. The newly added motors of more than 3 billion kilowatts will bring huge market space for high-efficiency motors.

　　Theoretically, the operating efficiency of an amorphous motor made of amorphous materials for the stator core can reach more than 95%, and the highest can reach 98%. Especially in some medium and high-frequency applications, the efficiency of traditional silicon steel sheet motors is very low, while the operating efficiency of amorphous motors is also above 90%, and the energy-saving potential contained in them is very considerable, which is why amorphous materials are used in high-efficiency motors The application provides a broad stage.

　　High-efficiency permanent magnet synchronous motors have been widely used in many fields. Because of their high efficiency and high-precision controllability, they have been widely used in everything from automated transportation operating systems to power system designs for electric vehicles. However, many fields - such as permanent magnet motors for electric vehicles need to be designed in a flat structure, so the disc permanent magnet motor must be designed in multi-stage, and the speed range of the motor needs to reach 2000~6000r/min, which leads to high motor speed. It will cause a sharp increase in the loss of ferromagnetic materials, reduce the efficiency of the motor, and bring great difficulty to the design of the cooling system. The disc-type permanent magnet motor made of amorphous material can greatly reduce the high-frequency iron loss of the motor, improve the efficiency of the motor, and optimize the design of the cooling system. Bottleneck problem in the field of electric vehicles.

　　2 Introduction to Amorphous Materials

　　2.1 Formation of amorphous material

　　After the metal is melted, the internal atoms are in an active state. Once the metal starts to cool, the atoms will gradually arrange in an orderly manner according to a certain crystal state as the temperature drops, forming a crystal. But if the cooling process is fast, the atoms are solidified before they can rearrange themselves, resulting in an amorphous state. Amorphous alloys are metal alloys that have a non-crystalline atomic structure. It is a rapid solidification process that is used to prepare amorphous alloys. Spray high-temperature copper water in a molten state onto a cooling roll rotating at high speed. The molten steel is rapidly cooled at a rate of one million degrees per second, and it only takes one thousandth of a second to reduce the 1300°C pot water to below 200°C to form an amorphous strip. The thickness of the amorphous strip is generally controlled between 0.02 and 0.03mm, which can realize online winding. The technological process is shown in Figure 1:

　　2.2 Characteristics of amorphous materials

    Compared with crystalline alloys, amorphous alloys have significant changes in physical, chemical and mechanical properties. Taking the amorphous alloy mainly composed of iron as an example, it has the characteristics of high saturation magnetic induction and low loss. However, amorphous alloy materials also have disadvantages that cannot be ignored; the hardness is too high and extremely brittle, and it is not easy to process and cut; the thickness is only 0.03mm, and the filling factor is low; it is also very sensitive to mechanical stress, which makes its application difficult.

　　2.3 Application of amorphous materials

    Because of such a series of excellent properties of amorphous materials, systematic theoretical and applied research has been carried out at home and abroad, and it has a broad application space in many fields such as electronics, aviation, aerospace, machinery, and microelectronics. At present, it has been widely used in various transformers and inductance products, but its application in the field of motors is still in its infancy. It is precisely because of the characteristics of amorphous materials that it has become a major topic at home and abroad to apply them to electrical products.

　　3 Advantages of amorphous motor

    Compared with traditional material motors, amorphous motors have superior performance and advantages. The following table lists the different characteristics of silicon steel sheet and amorphous material stator core by taking DW47 and Metglus2605SAl as examples.

    Through the comparison in Table 1, it is easy to infer the advantages of amorphous motors:

　　(1) High efficiency and energy saving

    Due to the low loss characteristics of the amorphous alloy material, the iron loss of the motor made of this material as the iron core is much smaller than that of the traditional silicon steel sheet iron core motor. It can be seen from Figure 2 that the loss of amorphous alloy materials at medium and high frequencies is only 1/8~1/10 of that of ordinary silicon steel sheets, and the trend is more obvious as the frequency increases. Therefore, the efficiency of the amorphous motor is higher than that of the traditional motor. Especially for medium and high frequency applications, the operating efficiency of the motor can be higher than 5%, and the energy saving effect is very obvious.

figure 2

　　(2) Power density and torque density

     The power P of the electric energy conversion of the large motor is proportional to the following three parameters: a) the magnetic flux of the magnetic field; b) the ampere-turn number A of the coil; c) the induced electromagnetic frequency of the first two fPαφAf magnetic flux φ= BS, where S is the magnetic circuit The effective cross-sectional area, B is the designed magnetic flux density. After the magnetic circuit size and magnetic circuit material are determined, the value of φ has been determined. The ampere-turn number A of the coil depends on the actual space and cooling conditions where the coil is installed, that is, it depends on the actual size of the motor. It can be seen that the higher the electromagnetic frequency f, the higher the power of the motor with the same size (that is, the same φA). Increased torque density.

　　4 Application of amorphous materials in high-efficiency motors

     The research and development of amorphous motors began in the early 1990s. In 1996, Light Engineering, Inc. (LE Company) in the United States successfully applied amorphous materials to motors and realized industrialization. After more than ten years of research and development, Xiangdian Laite Electric Co., Ltd. (hereinafter referred to as Xiangdian Wright) has developed a series of amorphous permanent magnet synchronous motors and generators, which are sold in batches in North America, Europe and Asia, and established the first production line of amorphous motors in China. A model of domestic amorphous materials applied to high-efficiency motors. This article will mainly introduce the application of amorphous materials in high-efficiency motors with Xiangdian Wright's axial magnetic field disc motor products.

　　4.1 Difficulties in the application of amorphous materials in the field of motors

　　1) Amorphous metal has high hardness and is difficult to form. It is easier to manufacture C-shaped or annular iron cores, but it is difficult to manufacture multi-slot iron cores for motors;

　　2) Restricted by the highest frequency of the motor driver, the base of the amorphous motor is generally designed to be above 500Hz, and the highest frequency can even reach above 1500Hz, which is a severe test for the motor driver;

　　3) Design methods for high-frequency motors cannot fully exploit the potential advantages of amorphous metals in increasing power density;

　　4) The saturation magnetization value of amorphous material is slightly lower than that of ordinary silicon steel material.

　　4.2 Amorphous motor design

　　Xiangdian Wright has built a disc-type amorphous motor research and development platform based on ANSOFT, using the 3D modeling and simulation capabilities of axial magnetic field motors released by the latest version of the software V15 to perform electromagnetic calculations and finite element analysis on disc-type amorphous motors. Xiangdian Wright has developed a series of amorphous disk permanent magnet synchronous motor products using this platform. Figure 3 and Figure 4 are schematic diagrams of the company's motor modeling and finite element analysis.

Fig.3 Full model of amorphous disk motorFig.4 Flux density of amorphous disk motor

　　Figure 5 shows the typical structure of the axial magnetic field disc permanent magnet motor designed by Xiangdian Wright. The structure fully considers the processing requirements of amorphous materials, and the core adopts an open slot structure. Iron cores are relatively easy to craft. The structure with few slots is adopted, and the formed coil is wound intensively to reduce the coil end and also reduce the loss caused by the effective material resistance. This structure is easy to realize automatic production in winding production and its off-line, and meets high-quality and large-volume production requirements. Improve the degree of mechanization of product production, thereby improving product quality.

　　Features of this structure:

　　1) The axial air gap structure makes it easy for the motor to realize a multi-stage structure, thereby realizing the high frequency of the motor;

　　2) The shape of the stator is relatively simple, the forming is easier, and the quality can be effectively guaranteed;

　　3) The motor winding adopts a 1/2 fractional slot structure, and a coil is placed on each tooth of the motor stator, which effectively reduces the coil increase and copper loss;

 

Fig.5 Structure of axial magnetic disk permanent magnet motorFig.6 Schematic diagram of coil

　　4) The axial magnetic field motor structure brings convenience to the design of the motor cooling system, which is also conducive to the design and manufacture of motors with higher power density;

　　5) Modular combined structure can be adopted, which is easy to realize serialized products;

　　6) The coil can be formed coil, which is easy to realize automatic operation;

　　7) It is suitable for mass production and can effectively reduce costs.

　　4.3 Introduction of mass-produced amorphous motors

　　1) The SG24N1 48VDC rechargeable generator does not need to run at a constant speed to generate electricity. The patented charge control technology can be used for charging lithium batteries, nickel-chloride batteries, and lead-acid batteries.

　　 2) SG24L1 Lighthouse Generator The generator is designed as four sets of single-phase, with high no-load voltage, which can realize the starting of metal halide lamps, and has high reliability.

　　3) Extended range generator for vehicle

 

　　4) Power range of amorphous drive motor system for electric vehicles: 25-200kW, improved efficiency in a large speed range, increased power torque density, air-cooled or water-cooled, multiple operating voltages, high-speed operating range, fully enclosed structure.

 

   5 Conclusion

    Through the successful application of amorphous materials in high-efficiency motors, the efficiency of the motor can be effectively improved, the power density ratio can be increased, and the volume weight can be reduced, so as to achieve energy saving and emission reduction, which is in line with national industrial policies. Amorphous high-efficiency motors have broad application prospects in high-frequency and high-speed, aviation, aerospace, military, and electric vehicles. The application of amorphous materials in high-efficiency motors has huge economic and social benefits.