Active Vibration Control of a Non-collocated AMBs Flexible Rotor System to Pass the First Bending Critical Speed

Abstract

In the industrial applications, active vibration control of flexible rotors supported by active magnetic bearings (AMBs) has been one of the difficulties and received wide attention. The problem of sensor-actuator non-collocation poses a greater challenge to the vibration control. In this paper, a mixed PID control strategy based on mode separation scheme is proposed for a non-collocated AMBs rotor system to pass the first bending critical speed. Firstly, the AMBs flexible rotor system with non-collocated sensors and actuators is modeled, and the non-collocation effects are analyzed. Then, detailed descriptions of the control method utilizing PID controller combined with phase compensators and phase shifters are presented for the non-collocated flexible rotor system. Phase to be compensated nearby the first bending modal frequency is analyzed. The root loci of the closed-loop AMBs flexible rotor system before and after introducing additional phase compensation are compared to evaluate the system stability. The simulation results validate the proposed control method.