Key technology of high temperature resistant motor for long-axis fan

As we all know, the motor is very important in the operation and power supply of machinery, and is also the mainstream mechanical driving equipment at present. High temperature resistant fans are popular because they can operate under extreme conditions. Recently, the wind of the high-temperature resistant motor of the long-axis fan is blowing very hard. Let's see how the key technology of the high-temperature resistant motor of the long-axis fan is realized.
With the continuous improvement of the performance of permanent magnet materials, especially the improvement of thermal stability and corrosion resistance of samarium cobalt permanent magnet, the gradual reduction of the price, and the further development of power electronic devices, at the same time, due to the advantages of AC permanent magnet motors such as small size, high power density, high efficiency, good characteristics, and good environmental adaptability, permanent magnet motors have been more and more widely used in the field of deep space exploration and development. The high-temperature resistant motor of long-axis fan is a complex electromagnetic system, and the key technologies involved include the following aspects.
1. Multi-physical field analysis method for electrical machines
In the wide temperature range from low temperature to high temperature, vacuum and other harsh aerospace environment, the electromagnetic parameters of permanent magnet motors change greatly, the material changes nonlinearly, the coupling relationship between the electromagnetic field, temperature field, fluid field, stress field and other physical fields is more complex, and the coupling relationship between the multiple physical fields that can be ignored under normal conditions becomes non-negligible, and becomes a key technical problem. The core loss, wind friction loss and motor temperature rise of the motor are not only closely related to the ambient temperature and pressure, but also affect each other. In the vacuum environment, the heat dissipation condition is special, which is related to the shape and surface properties of the adjacent parts. The thermal radiation has a nonlinear relationship with the surface temperature. The change from vacuum to high pressure affects the change of stress and material properties, which makes the multi-physical field modeling of the motor more difficult. Therefore, the coupling relationship of the physical fields in the permanent magnet motor is very complex in harsh environment, and it is very difficult to study the coupling relationship and dynamic change law of the physical quantities and physical fields.
The multi-physics field analysis methods of permanent magnet motor mainly include numerical analysis and finite element analysis. In numerical analysis, the common modeling methods include traditional matrix method, bond graph method, connection method, network method, etc. Academician Zhong Jue and others put forward the basic theory of global coupling analysis and coupling parallel design for complex electromechanical systems. Professor He Shanghong and others proposed the modeling matrix method for establishing complex network topology structure, and established a unified model of mechanical, electrical and hydraulic transfer matrix. In the literature, the generalized control system is used to establish a unified mathematical model for the multi-field coupling numerical simulation of the engine to solve the variable-domain difference problem of the gas, thermal and elastic coupling. The node mapping method of multi-field coupling is introduced, and the load transfer in the field is discussed.
However, there are still many problems in the coupled modeling and solution of the numerical analysis method. Due to too many assumptions and ignored factors, the calculation accuracy is not enough. In the aspect of finite element analysis, many CAD/CAE software companies, such as Ansys, Flux, SIMULIA, UGS, have developed multi-physical field coupling calculation tools, which have been applied in the fields of aeroacoustics, magnetohydrodynamics, dynamic fluid-structure coupling, etc., and the accuracy and efficiency of electromagnetic calculation have been gradually improved. The International Journal of Multi-Physics magazine, which was founded in the UK in 2007, holds a multi-field coupling conference every year, focusing on numerical models, model calculations and experimental investigations, including multi-physics field analysis of electrical machines.
To sum up, as an innovative type of high temperature resistant fan, the high temperature resistant motor of long-axis fan is also attracting people's attention now. The technical realization of the high-temperature resistant motor of the long-axis fan needs a certain foundation, including the improvement of the circuit and the structure of the high-temperature resistant motor. What we can be sure of is that the high-temperature resistant motor of long-axis fan will occupy an important position in the future.