Principle and performance analysis for six‐pole hybrid magnetic bearing with a secondary air gap

Abstract

In order to reduce the non-linearity of radial suspension forces of the three-pole hybrid magnetic bearing and further reduce the cost and power consumption, an AC six-pole hybrid magnetic bearing with secondary air gaps is proposed. First, the structure and working principle of the AC six-pole hybrid magnetic bearing with secondary air gaps are introduced, and the mathematical model of suspension forces are derived. Second, on the basis of the mathematical model, the linearity and coupling characteristics of the radial suspension forces are analysed, and then the suspension forces are simulated and verified by the finite element method (FEM). Then, the correlation performance indexes are compared with the six-pole hybrid magnetic bearing without secondary air gaps. Finally, an experimental platform is built, and suspension and disturbance tests are carried out. The research results show that the maximum bearing capacity of the six-pole hybrid magnetic bearing with secondary air gaps is 184% of the six-pole hybrid magnetic bearing without secondary air gaps.