Vibration Suppression of Multi-Stage-Blade AMB-Rotor Using Parallel Adaptive and Cascaded Multi-Frequency Notch Filters

Abstract

The application of active magnetic bearings (AMBs) in high-speed rotating machinery faces the challenge of micro-vibration. This research addresses the vibration control of a high-speed magnetically suspended turbo molecular pump (MSTMP) with rotor mass imbalance vibration and multi-stage-blade modal vibration. A novel integrated AMB controller consisting of parallel co-frequency adaptive notch filter (ANF) and cascaded multi-frequency improved double-T notch filters (DTNFs) is proposed. To suppress rotor mass imbalance vibration, a bandwidth factor rectification method of the ANF based on displacement stiffness perturbation is designed. To suppress multi-stage-blade modal vibration, a multi-objective constrained optimization method of cascaded improved DTNFs based on linear normalization is designed. Simulation and experimental results validate that the proposed structure improvement of the addition of an AMB controller and multi-parameter optimization of the algorithm can effectively improve not only the phase stability margin and the notch vibration performance of the magnetically suspended rotor (MSR) system but also the efficiency and practicability of the algorithm. At rotational speeds of 12,000 rpm, 15,000 rpm, 18,000 rpm, and 21,000 rpm, the suppression of co-frequency synchronous vibration is approximately maintained between −30.94 dB and −30.56 dB. At the rated speed of 24,000 rpm, compared with other algorithms, the value of the rotor displacement converges from 0.08 mm to 0.03 mm, a reduction of 62.50%. The convergence time decreases from 3.67 s to 2.85 s, a reduction of 22.34%.

Keywords

• active magnetic bearing
• magnetically suspended turbo molecular pump
• rotor mass imbalance vibration
• multi-stage-blade modes
• notch filter
• multi-objective constrained optimization