Study of repulsive permanent magnetic levitation mechanism and its dynamic characteristics

Permanent magnet magnetic levitation (PMFL) system has the characteristics of zero-power levitation, strong load-carrying capacity and self-stabilization, so it has obvious advantages in the application of rail transportation and heavy-duty transmission and other fields. However, due to the lack of active control of electromagnetism and the existence of multi-point coupling, it is easily affected by external factors, and its dynamic characteristics and its complexity. This paper aims to reveal the levitation mechanism of permanent magnet magnetic levitation system and the coupling motion law of bogie by combining theoretical analysis and experimental verification. Firstly, the proportional and exponential correction coefficients for the magnetic induction strength are introduced to establish an analytical model for the levitation force. Secondly, the three-dimensional dynamic characteristic model of the bogie is established by analyzing the running attitude and external disturbing factors, revealing the four-point levitation coupling mechanism, and judging its stability by using the motion control theory. On this basis, input and output decoupling is realized by the method of coordinate transformation. Finally, through simulation analysis and physical experiments, the bogie motion law under various complex working conditions is explored, and the validity and reliability of the research is proved.