Permanent magnet motor uses permanent magnet to generate the magnetic field of the motor, without excitation coil nor excitation current, high efficiency and simple structure, is a good energy-saving motor, with the advent of high-performance permanent magnet materials and the rapid development of control technology. Permanent magnet motors will become more widely used. 

Development history of permanent magnet motor: 

The development of permanent magnet motor is closely related to the development of permanent magnet materials. China is the first country in the world to discover the magnetic properties of permanent magnetic materials and apply them to practice. More than two thousand years ago, China made the compass by using the magnetic properties of permanent magnetic materials, which played a huge role in navigation, military and other fields and became one of the four great inventions in ancient China. 

With the rapid development of various motors and the invention of current magnetization device, people have carried out in-depth research on the mechanism,composition and manufacturing technology of permanent magnet materials, and have discovered carbon steel, tungsten steel (maximum magnetic energy product of about 2.7 kJ/m3), cobalt steel (maximum magnetic energy product of about 7.2 kJ/m3) and other permanent magnet materials.    

Characteristics and applications of permanent magnet motor:

Compared with traditional electric excitation motor, permanent magnet motor, especially rare earth permanent magnet motor has simple structure and reliable operation. Small size, light weight; Small loss, high efficiency; The shape and size of the motor can be flexible and varied, etc. Therefore, the application range is extremely wide, almost throughout the aerospace, national defense, industrial and agricultural production and daily life of each field. 

The important role of permanent magnet motor in various application fields:

Energy-saving rare earth permanent magnet motors are mainly targeted at consumption, such as rare earth permanent magnet synchronous motors used in textile and chemical fiber industry, petroleum, mining, rare earth permanent magnet synchronous motors in coal mine transportation machinery, rare earth permanent magnet synchronous motors drive various pumps and fans. 

Various rare earth permanent magnet motors are used by various types of vehicles (cars, motorcycles, trains), and rare earth permanent magnet motors are the largest market. According to statistics, about 70% of rare earth permanent magnet motors are used in cars. The limousine has more than 70 sets of motors for various applications. Because the requirements of various automobile motors are different, the choice of permanent magnet materials is not the same. Motor magnet used in air conditioning, fans, electric Windows, from the point of view of price, the future will continue to ferrite advantage. Sm-co sintered magnets are still used for ignition coils, drives and sensors. In addition, auto parts, also electric vehicles can not be ignored, as a kind of environmental protection (EV) and hybrid electric vehicle (HEV). 

Rare earth permanent magnet motor AC servo system a set of electronic, high performance, speed control system of mechatronics machinery. The system is a self - controlled permanent magnet synchronous motor. The system is used in the development of CNC machine tools, flexible manufacturing technology;  Also used in electric vehicles, rather than traditional thermal vehicles, vehicle emissions are free. Rare earth permanent magnet motor is a promising high-tech industry. 

The new field is mainly for the new air conditioning and refrigerator low-power rare earth permanent magnet synchronous motor frequency control system support, used in all kinds of rare earth permanent magnet DC micromotor wireless electric gadgets, rare earth permanent magnet brushless DC motor is different power instruments. This kind of motor is also in great demand.

The advantages of rare earth permanent magnet materials in aerospace applications make them very suitable for aero-engine applications. Although there are some applications for rare-earth permanent magnet motors in air (such as generator voltage and short circuit protection, etc.), experts at home and abroad agree that rare-earth permanent magnet motors are an important development direction for the next generation of aero engines.