Experimental Identification of Residual Unbalances for Two-Plane Balancing in a Rigid Rotor System Integrated with AMB

An experimental dynamic balancing procedure is presented for a rigid rotor system supported on conventional bearings and integrated with active magnetic bearing (AMB). The residual unbalances present in the rotor system are the major causes of fatigue failure of the system at high speeds. So, it is necessary to balance the system to avoid any damage to the system. AMBs are utilized to suppress the vibration of the system through controlled magnetic forces. In this work, AMB is utilized to suppress the vibration of the system using active control through a PD controller. The balancing procedure can be carried out with less vibration in the presence of AMB. Also, after balancing, the AMB in the system can take care of abrupt rise in system response with less power consumption in vibration control. An eight-pole actuator is utilized for generating magnetic force in the rotor system. The PD controller is developed on the dSPACE and Simulink platform for the generation of control current. The measured displacement response through eddy current probes is utilized in the influence coefficient method (ICM) to obtain the balance masses at two balancing planes for dynamic balancing of the system. The obtained balance masses are placed at the respective balancing planes, and the reduction in vibrational response is observed. In comparison with the displacement responses before and after balancing, the displacement is found to be reduced after balancing.