The Effect of Current Control Strategies on Power Consumption of a Magnetically Levitated Turbomolecular Pump

This paper presents a novel current control technique called ´variable bias current control (VBCC)´ developed to minimize the power consumption of active magnetic bearings (AMB) used in turbomolecular pumps. Initially, the mathematical model of the AMBs and the TMP are derived to obtain the simulation model of the system. Then, the effectiveness of bias current on energy consumption is investigated for differential and unidirectional current control strategies. It is shown that it is beneficial to optimize the bias current according to the operating conditions. Finally, the simulation results are utilized to successfully demonstrate the effectiveness of the VBCC technique