Seven major problems in high speed motor design? Whether it is domestic or foreign, high-speed motors still have problems that need to be solved in design and analysis. Specifically, high-speed motors have the following problems in design and analysis.
Due to the weak research foundation, China's high-speed motor industrialization level is relatively low, compared with foreign countries, there is still a big gap, especially for high-power high-speed motors and ultra-high-speed high-speed motors above MW level. There are few applications in design and analysis. many problems.
High-speed motors generally refer to motors with a speed exceeding 10,000 r/min or a difficulty value exceeding 100,000. At present, there are mainly induction motors, inner rotor permanent magnet motors, switched reluctance motors and a few outer rotor permanent magnet motors. Claw pole motor, etc.
The high-speed motor is characterized by small size, high power density, and can be directly connected to high-speed loads, eliminating the need for traditional mechanical speed-increasing devices, reducing system noise and improving system transmission efficiency. High-speed motors can be used in a wide range of applications, including high-speed grinding machines, fuel cells, energy storage flywheels, international electricians, etc., with good market prospects.
Foreign research on high-speed motors has a considerable foundation and a high level of industrialization. Due to the late start of China, the development is mostly concentrated in the small and medium power and low speed range. The industrialization level of high speed motor is low, and there is a certain gap compared with foreign countries.
However, whether it is domestic or foreign, high-speed motors still have problems that need to be solved in design and analysis. Specifically, high-speed motors have the following problems in design and analysis.
First, the technology of analyzing high-speed motors based on electromagnetic field, stress field, rotor dynamics, fluid field and temperature field and other multi-physics coupling methods is still not mature;
Second, high-speed bearings face large problems. For example, ball bearings cannot withstand excessively high rotational speeds, air bearings have limited load carrying capacity, and magnetic suspension bearings are complicated to control and expensive.
Third, the rotor dynamics design technology of high-power high-speed motors has not been perfected, and the development of transformation systems, control systems, and real-time monitoring systems is relatively weak;
Fourth, the high-power rate high-speed permanent magnet motor has a complicated cooling structure, and the combination of air cooling and water cooling is adopted, and the cooling effect is limited;
Fifth, the development of high-speed permanent magnet motors in the direction of ultra-high speed and high power is restricted by the low tensile strength and poor temperature resistance of permanent magnets;
Sixth, the alloy protective sleeve of the surface-mounted permanent magnet motor has large eddy current loss, and the thermal conductivity of the carbon fiber protective sleeve is poor, which is not conducive to the heat dissipation of the rotor;
Seventh, conventional laminated rotors cannot withstand large centrifugal forces, and solid rotors have large eddy current losses.
Therefore, the development and research of high-speed motors in the future will be based on the above key issues, such as multi-physics and multi-disciplinary coupling design, the development of high-strength and high-temperature-resistant permanent magnet materials, research on high-strength rotor lamination materials and structures, Develop high-speed motor control systems, etc.