Analysis of Torque and Suspension Force Fluctuation of a Bearingless Brushless DC Motor Based on Cogging Boundary Condition

摘要

Aiming at problems of suspension force ripple in the suspension windings control methods of bearingless brushless direct current motors, eight kinds of conduction rules under different boundary conditions are deduced based on the principle of determining the conduction phase of suspension windings. Then, suspension force ripples and torque ripples of these rules are compared and analyzed with the FEA software to obtain the optimal suspension conduction rule. Finally, the influence of torque winding loading on suspension force ripple is analyzed by using air gap magnetic density waveforms. And conduction intervals of suspension windings and pole embrace are further optimized, which provides theoretical support for suspension optimization control methods of bearingless brushless DC motors.